12th English Revision Test Question Paper 2022

CHENGALPATTU DISTRICT SECOND ASSESSMENT TEST - 2020 XII - ENGLISH Time: 3.00hrs  Mark: 90 Part - I Note: Answer all the questions: 20x1=20  Choose the most appropriate answer from the given four alternatives and the option code and the corresponding answer. Choose the most appropriate synonyms of the underlined words in the following sentences. 1. My English teacher persuaded me to take good marks in all the subjects.  a) encouraged  b) stimulated  c) disappointed  d) followed 2. Desdemonce is on artless character in the paly “othello”. a) canning  b) shread  c) Innocent  d) Clever 3. During the freedom struggle, the British Govenement respected and his nobility  a) Indetatigable  b) persevrence c) adament  d) honest Choose the most appropriate antonyms of the underlined words in the following sentence. 4. The students are very brisk when they are at home. a) active  b) dull  c) fast  d) lazy 5. Everybody likes Mother Therasa’s selfless character. a)Selfish  b) Intelligent  c) humble  d) broadminded 6. During the lockdown the entire city seems to be deserted look. a) crowded  b) secured  c) fertile  d) desolate 7. Form a new word by adding a suitable prefix to be underlined word. The cultivated land is fertile a) non_  b) in_  c) un_  d) dis_ 8. Choose the appropriate suffix for the following underlined word.  I like his friend a) ship  b) ness  c) by  d) less 9. Repalce the, underlined word with a suitable pharasal verb.  The fire brigade douse the fire. a) put off  b) put on  c) put out  d) put in 10. Fill in the blank with the correct form of verb given in the brackets.  Where ____ your last holidays? (you spend) a) You spent  b) you are spending  c) you were spending  d) did you spend 11. Fill in the blank with modal auxiliaries.  You _____ not go to the market.as I have bought vegetables. a) will b) should  c) need  d) can. 12. Fill in the blanks with suitable prepositional pharse which is given below.  ______ Gandhiji ahimsa means infinite love. a) In favour of b) On account of  c) Accoring to  d) on the whole 13. Fill in the blanks with suitable preposition.  There was a skirmisth ______ my brother and sister. a) among  b) over  c) with  d) between 14. Choose the appropriate linker from the options and fill in the blank.  _____ you register your name, you cannot participate in the competion. a) if  b) unless  c) as soon as  d) though 15. Fill in the blanks with appropriate correlative conjunctions.  Amit did not know ____ his father met his class teacher _____ not. a) such that  b) both and  c) whether or  d) neither nor 16. Choose the disyllabic word.  a) benefit  b) again  c) weight  d) strength 17. Fill in the blank with the correct from of the verb.  My mother ____ to temple every friday a) go  b) is going  c) goes  d) was going 18. Fill in the blank with modal auxiliary.  I _____ speak English (ability) a) will  b) shall  c) may  d) can 19. Fill in the blank with most suitable preposition. The prayer session will be held _________ Friday a) at  b) on  c) with  d) of 20. Form a new word by adding a suitable prefix to the underlined word.  It is rather an expensive compliment. a) un_  b) in_  c) dis_  d) non_ Part - II Section - I Read the following sets of poetic lines and answer any four sets. 4x2=8 21. “A gray baboon sits statue – Like alone”  a) where did the baboon sit?  b) mention the figure of speech? 22. “Like a huge python, winding round and round The rugged trunk, indented deep with scars A creeper climbs, in whose embraces bound No other tree could live”  a) what is winding round the tree like a python? b) which tree is referred to in the above line? 23. “And far and near kokilas hail the day;  And to their pastures wend our sleepy cows; ” a) what are kokilas? b) How do the cows go to their pastures? 24. “By that hoar tree, so beautiful and vast  The water lilies – spring, like snow enmassed”. a) Where do the lilies spring? b) Mention the figure of speech? 25. “What is that dinge like murmur that I hear Like the sea breaking on a shingle-beach It is the tree's lament, an errie speech.” a) what is that the poet hears? b) what does the tree lament? 26. “Thy form, o Tree, as in my happy prime I saw thee, in my own loved native claim. Therefore, I fain would consecrate a say unto thy honour, Tree, beloved of those.” a) what is addressed in the above line? b) what would the poet do in honour of tree? SECTION - 2 Do as directed Answer any three questions: 3x2=6 27. Change the direct speech into Reported form  Ann said to Tom, ” Would you like to come to the party with us tomorrow?” 28. Fill in the blanks with suitable homophones or confusables.  The _____ has kept his ____ on the dinning table. ( Wallet/ valet) 29. Combine the sentences and rewrite them using the words given in the brackets.  A libery is a public place. We see a number of books kept there for reading. (where) 30. Complete the sentence using prepositions given in brackets  [into, on, in front of, under] a) The boy jumped _______ a narrow stream. b) Afsar will meet me ______ Thursday morning. PART – III SECTION – 1 Explain any two of the following with reference to the context. 2x3=6 31. “Like a huge python, winding round and round The rugged trunk, indented deep with scars.” 32. “Beneath it we have played; though years may roll, O sweet companions,loved with love intense, For your sakes, shall the tree be ever dear” 33. A gary baboon sits statue like alone watching the sunrise; while on lower boughs His puny off spring leap about and play; SECTION – 2 Answer any of the following qusetions in not more than 30 words. 2x3=6 34. What were the various jobs undertaken by Nicolo and Jacobo? 35. Describe the appearance of Nicolo and Jacobo. 36. How did the narrator help the boys? SECTION – 3 Answer any three of the following: 3x3=9 37. Study the following table, and write three sentences on your inference about the data. Average Annual rainfall in the Southern States of India in the year 2012

12th Physics Chapter 2 Important Questions With Answers

 CURRENT ELECTRICITY

UNIT -2

2 & 3 Marks:

1. Define electric current. Give its SI unit.

Electric current is defined as the rate of flow of charges.

SI unit: ampere

I = q/t

2. Why current is a scalar?

Current is defined as scalar product of current density and area vector.

I=j.Ā

Current can be positive or negative depending on the choice of unit vector normal to the surface area. Hence, current is a scalar.

3. Define one ampere.

One ampere of current is equivalent to 1 coulomb of charge passingthrough perpendicular cross section in 1 second.

1A= 1C/1s

4. What is meant by drift velocity? Give its unit.

Drift velocity is defined as the average velocity acquired by the electrons when it is subjected to an electric field. 

Unit: ms-1

.

5. Define mobility. Give its unit.

Mobility is defined as the drift velocity acquired per unit electric field.

SI unit: m²V-¹s-¹

6. Distinguish between drift velocity and mobility.

7. Define current density. Give its unit.

It is defined as the current per unit area of cross section of the conductor.

J = I / A

SI unit: Am-2

8. State Microscopic form of Ohm’s law.

Magnitude of current density is directly proportional to the applied electric field.

9. State Ohm’s law or macroscopic form of Ohm’s law.

At constant temperature, the steady current flowing through the conductor is directly proportional to the potential difference between the two ends of the conductor.

V=IR

10.What are ohmic and non ohmic devices?

Ohmic devices:

The devices which obey ohm’s law are called ohmic devices.

I α V holds good for ohmic devices.

V – I graph is a straight line.

Examples: Metals.

Non-Ohmic devices:

The devices which do not obey ohm’s law are called Non-ohmic devices.

I α V does not hold good. (V-I relation is complex)

V- I graph is non-linear.

Examples: Diodes, Transistors.

11.Define Resistance. Give its unit.

It is the ratio of potential difference across the conductor to the current through the conductor.

R=V/I

SI unit: Ω

12.Define electrical resistivity.

It is defined as the resistance offered to the flow of current by a conductor of unit length and unit area of cross section.

SI unit: Ωm

13. What are the factors on which electrical resistivity depends?

The resistivity of a material is

i) inversely proportional to the number density (n) of the electrons

ii) inversely proportional to the average time between the collisions(τ).

14.Define electrical conductivity.

It is the reciprocal of resistivity.

SI unit: Ω-1m-1

15.What is meant by superconductivity? What are superconductors?

The ability of certain metals, their compounds and alloys to conduct electricity with zero resistance at very low temperatures are called superconductivity. Such materials are called superconductors.

16.Define Temperature coefficient of resistance.

It is defined as the ratio of increase in resistance per degree rise in temperature to its resistance at 0⁰C.

α= 1/Ro ∆R/∆T

SI unit: per ⁰C

17.Define Temperature coefficient of resistivity.

It is defined as the ratio of increase in resistivity per degree rise in temperature to its resistivity at 0⁰C

α =∆ρ/ρo∆T

SI unit: per ⁰C

18.Define electric energy and electric power.

Electric energy: It is defined as the capacity to do electrical work.

Electric Power: It is defined as the rate at which the electrical potential energy is delivered.

19.Give the practical unit of electrical energy.

The practical unit of electrical energy is kilowatt hour (kWh)

1 kWh = 3.6 x 10⁶J

20.Define electromotive force.

Electromotive force is the amount of work done by a battery to move some charge around the circuit.

21.Define internal resistance.

Internal resistance is the resistance offered to the flow of charges within the battery.

22. State Kirchhoff’s current rule.

Algebraic sum of the currents at any junction of a circuit is zero.

23.State Kirchhoff’s voltage rule.

In a closed circuit, algebraic sum of the products of the current and resistance of each part of the circuit is equal to the total emf in the circuit.

24.Why is copper wire not suitable for a potentiometer?

Copper wire is not suitable for potentiometer because it has high temperature coefficient of resistance and low specific resistance.

25. What is meant by Seebeck effect or Thermoelectric effect?

▪ Two dissimilar metals connected to form two junctions is called thermocouple.

▪ When these junctions are maintained at different temperatures, an

emf developed in the circuit known as thermo electric emf.

▪ The current through the circuit is called thermoelectric current.

▪ This effect is called Seebeck effect or thermoelectric effect.

26.Give the applications of Seebeck effect.

i) Thermoelectric Generators,

ii) In automobiles to increase fuel efficiency,

iii) Measure temperature difference in thermocouples and thermopiles.

27.What is meant by Peltier effect?

When an electric current is passed through a circuit of a thermocouple, heat is evolved at one junction and absorbed at the other junction.

28. Define Thomson effect.

If two points in a conductor are at different temperatures, the density of electrons at these points will differ and as a result the potential difference is created between these points.

12th Bio Zoology Chromosomal Mutations Notes

 CHROMOSOMAL MUTATIONS

Altering the chromosomal shape or modifying the number of chromosomes in a cell can also impact the genome on a broader scale. Chromosome mutations or chromosomal aberrations are the names given to these large-scale changes. 

Gene mutations are changes inside a gene, whereas chromosomal mutations are changes to a chromosomal area that includes many genes. Microscopy, genetic analysis, or both can be used to identify it. Gene mutations, on the other hand, are never visible under a microscope. There are two types of chromosomal mutations:

1. Changes in chromosome number &

2. Changes in chromosome structure.

I. CHANGES IN CHROMOSOME NUMBER

Living creatures have a set number of chromosomes in each cell. It differs across species. Even though certain plant and animal species have the same number of chromosomes, they will not have the same characteristics. As a result, the number of chromosomes does not distinguish one species from another; rather, the form of hereditary material (gene) in chromosomes defines species characteristics.

Due to additions or deletions of individual chromosomes, the number of chromosomes in somatic cells might fluctuate. Ploidy or numerical chromosomal aberrations is the term for this disorder. There are two different forms of ploidy.

1. Ploidy involving individual chromosomes within a diploid set (aneuploidy)

2. Ploidy involving entire sets of chromosomes (euploidy)

(1) ANEUPLOIDY

 It's a situation in which the number of diploid cells changes due to the addition or deletion of one or more chromosomes. Aneuploids or heteroploids are organisms that demonstrate aneuploidy.

They are of two types,

1. Hyperploidy &

2. Hypoploidy.

1. HYPERPLOIDY

 Addition of one or more chromosomes todiploid sets are called hyperploidy. Diploid Set of chromosomes represented as disomy.

Hyperploidy can be divided into three types.

They are as follows,

(a)Trisomy

Simple trisomy(2n+1) is the addition of a single chromosome to a diploid set. Blackeslee (1910) discovered trisomics in datura Stramonium for the first time (jimson weed). However, it was later discovered in Nicotiana, Pisum, and Oenothera. Double Trisomy (2n+1+1) is the insertion of two individual chromosomes from distinct chromosomal pairs to typical diploid sets.

(b) Tetrasomy

Tetrasomy is a condition in which there are four copies of a DNA molecule. Tetrasomy (2n+2) and double tetrasomy (2n+2+2) are the addition of a pair or two individual pairs of Chromosomes to a diploid set, respectively. Wheat has all of the potential tetrasomics.

(c)Pentasomy

Pentasomy (2n+3) is the addition of three distinct chromosomes from different chromosomal pairings to a typical diploid set.

2. HYPOPLOIDY HYPOPLOIDY HYPOPLOIDY

Hypoploidy is the loss of one or more chromosomes from the Diploid set in a cell. It may be classified into two categories.

They are, 

(a) Monosomy

Monosomy refers to the loss of a single chromosome from a diploid set (2n-1). Double monosomy (2n-1-1) and triple monosomy (2n-1-1-1) refer to the loss of two or three individual chromosomes, respectively. In maize, double monosomics have been detected.

(b) Nullisomy

 Nullisomy (2n-2) and double nullisomy (2n-2-2) refer to the loss of a pair of homologous chromosomes or two pairs of homologous chromosomes from the diploid set. Monosomic plants that are selfed create nullisomics. They are almost always fatal.

(Ii) Euploidy

Euploidy is the presence of one or more fundamental sets of chromosomes in an organism. Monoploidy, diploidy, and polyploidy are the three euploidy types. Diploid is the state of having two sets of chromosomes in an organism or somatic cell (2n). Gametic chromosomal number, or haploid, is half the number of somatic chromosomes (n).

It's important to distinguish between haploidy (n) and monoploidy (m) (x). The ordinary wheat plant, for example, has 2n=6x=72 chromosomes, making it a polyploidy (hexaploidy). It has 36 haplotypes (n), but only 12 monoploids (x).

As a result, the haploid and diploid conditions appeared in a regular sequence, and the same number of chromosomes was maintained from generation to generation, while monoploidy occurs when an organism is polyploid. In a true diploid both the monoploid and haploid chromosome number are same. Thus a monoploid can be a haploid but all haploids cannot be a monoploid.

12th Computer First Revision Exam Question Paper

 Chengalpattu District

Second Assessment test - 2022

12th - Computer science

Time Allowed: 3.00hrs 

Max.Marks: 70

Instructions: (1) Check the question paper for fairness of printing.

 (2) Use Blue or Black ink to write and underline and pencil to draw diagram.

Part - I

I. Note: (1) All Questions are compulsory 15 X 1 = 15

 (2) Choose the most appropriate answer form the given four

 alternatives and write the option code and the corresponding answer.

1. Which of the following is a unit of code that is often defined within a greater code

structure?

A) Subroutines

(B) Function 

(C) Files 

(D) Modules

2. Which of the following functions that retrieve information from the datatype?

(A) Constructors 

(B) Selectors 

(C) Destructor 

(D) Recursive

3. Which of the following functions that build the abstract data type?

(A) Constructors 

(B) Selectors 

(C) Destructor 

(D) Recursive

4. The process of binding a variable name with an object is called

(A) Scope 

(B) Mapping 

(C) late binding 

(D) early binding

5. Containers for mapping names of variables to objects is called

(A) Scope 

(B) Mapping 

(C) Binding 

(D) Namespaces

6. From the following sorting algorithms which algorithm needs the minimum number of

swaps?

(A) Bubble sort 

(B) Quick sort 

(C) Merge sort 

(D) Selection sort

7. Which of the following is not a token?

(A) Interpreter 

(B) Identifiers 

(C) Keywords 

(D) Operators

8. Which sorting is called simple sorting algorithm

(A) Bubble sort 

(B) Quick sort 

(C) Merge sort 

(D) Selection sort

9. Binary search also called

(A)Linear Search 

(B) Boolean Search

(C) Number Search 

(D) Half-interval search algorithm.

10.Who developed Python ?

(A) Bill Gates 

(B) Ritche

(C) Sunder Pitchai 

(D) Guido Van Rossum

11.In Python, programs can be written in --- ways?

(A) 4 

(B) 3 

(C) 2 

(D)1

12.IDLEExpansion

(A) Integrated Design LearningEnvironment

(B) Integrated Development LearningEnvironment

(C) Integrated Develop LearningEnvironment

(D) Insert Development LearningEnvironment

13.This symbol is used to print more than one item on a singleline.

(A) Semicolon(;) 

(B) Dollor($) 

(C) comma(,) 

(D) Colon(:)

14.Which of the following character is used to give comments in Python Program ?

(A) # 

(B) & 

(C) @ 

(D)$

15.Which operator is also called as Conditionaloperator?

(A) Ternary 

(B) Assignment 

(C) Logical 

(D) Relational

PART - II

Answer any 6 Questions. Q.No. 19 is Compulsory. (6 X 2=12)

16.What is asubroutine?

17. Differentiate Constructor andSelector.

18.What is ascope?

19.Write the inference you get from Y :=(100)

20.What do you mean by algorithmic strategy?.

21.What is anAlgorithmic solution?

22.What is searching? Write its types.

23.Write short notes on Tokens.

24.What are the different operators that can be used in Python?

PART - III

Answer any 6 Questions. Q.No. 29 is Compulsory. (6 X 3=18)

25. Differentiate Algorithm and program

26.Identify Which of the following are constructors and selectors?

(a) N1=number()

(b) accetnum(n1)

(c) displaynum(n1)

(d) eval(a/b)

(e) x,y= makeslope (m), makeslope(n)

(f) display()

27. Define Local scope with an example.

28. Define Global scope with an example.

29.What are the two different phases of Analysis of algorithm

30.Write short notes on Escape sequences with example

31.What are the assignment operators explain with example that can be used in Python?

32.Explain Ternary operator with examples.

33.What are string literals? Explain.

PART - IV

Answer all of the following Questions. (5 X 5 = 25)

34. What are called Parameters and write a note on

(i) Parameter without Type (ii) Parameter with Type

(OR)

Discuss in detail about Tokens in python.

35.LEGB rule with example.

(OR)

What is Binary search? Discuss with example

36. Discuss about Linear search algorithm.

(OR).

Explain the characteristics of analgorithm.

37.Explain the Bubble sort algorithm with example.

(OR)

Explain input() and print() functions with examples.

38. Describe in detail the procedure Script mode programming.

(OR)

Explain the Selection sort algorithm with example.

12th Physics Chapter 1 Important Questions With Answers

 

12TH PHYSICS UNIT 1 IMPORTANT QUESTIONS WITH ANSWERS

2 Marks:

1. Electrostatics

The branch of physics which deals with stationary charges is called Electrostatics.

2. Triboelectric charging:

Charging the objects through rubbing is called triboelectric charging.

3. Coulomb's law:

Coulomb's law states that the electrostatic force between two point charges is directly proportional to the product of the magnitude of the two point charges and is inversely proportional to the square of the distance between the two point charges.

4. Superposition principle:

The total force acting on a given charge is equal to the vector sum of forces exerted on it by all the other charges.

5. Electric field:

Electric field is defined as the force experienced by a unit charge placed at that

point.

6. Electric dipole:

Two equal and opposite charges separated by a very small distance constitute an electric dipole.

7. Electric dipole moment:

The magnitude of the electric dipole moment is equal to the product of the

magnitude of one of the charges and the distance between them. p = 2qa

8. Electric potential:

The electric potential at a point is equal to the work done by an external force to bring a unit positive charge with constant velocity from infinity to that point in the region of the external electric field.

9.Electric flux:

The number of electric field lines crossing a given area kept normal to the electric field lines is called electric flux. It is usually denoted by the letter ΦE. Its unit is N m2 C-1. Electric flux is a scalar quantity and it can be positive or negative.

10.Gauss law:

Gauss’s law states that the total electric flux ΦE through the closed surface is equal to 1/ε0 times the net charge enclosed within that closed surface.

Φ = Qenclosed / €o

Here Qencldenotes the charges inside the closed surface.

11. Capacitance:

The capacitance C of a capacitor is defined as the ratio of the magnitude of charge on either of the conductor plates to the potential difference existing between the conductors.

C = Q / V

The SI unit of capacitance is coulomb per volt or farad (F)

12. Applications of capacitors:

(a)The flash which comes from the camera is due to the energy released from the capacitor, called a flash capacitor.

(b) During cardiac arrest, a device called heart defibrillator is used to give a sudden surge of a large amount of electrical energy to the patient’s chest to retrieve the normal heart function. This defibrillator uses a capacitor of 175 μF.

(c) Capacitors are used in the ignition system of automobile engines to eliminate

sparking.

(d) Capacitors are used to reduce power fluctuations and to increase the efficiency

of power transmission.

13. Disadvantage of capacitor:

Even after the battery or power supply is removed, the capacitor stores charges and energy for some time. For example if the TV is switched off, it is always advisable to not touch the back side of the TV panel.

14. Action of points or corona discharge:

Leakage of charges from the sharp ends of a charged conductor.

15. Principle and Uses of Van de Graaff generator:

Principle: Action of points and Electrostatic induction.

Uses: (i) Used to produce a large potential difference of 107 V.

(ii) Used to accelerate positive ions (protons and deuterons) for nuclear disintegrations.

3 Marks:

1. Basic properties of charges

(i) Electric charge

Materials are made up of atoms. Atoms are made up of protons, neutrons and electrons.

S.I unit of charge is coulomb.

(ii) Conservation of charges

Charges are neither created nor destroyed. They can be transferred from one

object to other. Net change in the charge will always be zero. This is called

conservation of charges.

(iii) Quantisation of charges

The charge q of any system is equal to the integral multiple of the fundamental

unit of charge e.

q = ne.

Here n is any integer (0, ±1, ±2, ±3, ±4............. ). This is called quantisation of

electric charge.

The value of e = 1.6 × 10-19C. The charge of an electron is −1.6 × 10-19C and the charge of the proton is +1.6 × 10-19C. Charge of any system is quantised. It can take only discrete set of values.

2. Important aspects of coulomb’s law:

(i) Coulomb's law:

Coulomb's law states that the electrostatic force between two-point charges is directly proportional to the product of the magnitude of the two-point charges and is inversely proportional to the square of the distance between the two point charges.

(ii) Direction of coulomb’s force always act along the line joining the two charges.

(iii) In SI units, k = 1/4πε0 and its value is 9 × 109 N m2 C-².

Here εo is the permittivity of free space or vacuum and the value of εo = 8.85 x 10 -12 N-1 m-²C2

(iv) One coulomb:

One coulomb is the charge which when placed at a distance of 1m in air from an equal and similar charge will experience a force of 9 × 109 N

(v) The force between two-point charges in a medium is always less than that in vacuum.

The relative permittivity εr = ε / εo.

For vacuum or air, εr = 1 and for all other media εr > 1.

3. Comparison of Coulomb force with Gravitational force:

Coulomb force:

(i) Coulomb force between two charges can be attractive or repulsive.

(ii) k = 9 × 109 N m2 C

-2

(iii) k > G

(iv) Coulomb force depends on the medium

(v) Coulomb force is true only for point charges.

(vi) When the charges are in motion, in addition to Coulomb force, Lorentz force also comes into play.

Gravitational force:

(i) Force between two masses is always attractive.

(ii) G = 6.67 x 10 -11 N m2kg-2

(iii) G < k

(iv) Gravitational force does not depend on the medium

(v) Gravitational force is obeyed even in the case of larger mass.

(vi) Gravitational force between two masses is the same whether the masses are at rest or motion.

4. Important aspects of electric field:

(i) For a positive source charge, the electric field points radially outward.

(ii) For a negative source charge, the electric field points radially inward.

(iii) The force experienced by a test charge q0 is given by, F = q0E

(iv)Electric field depends only on the source charge.

(v) As distance increases, electric field decreases.

(vi)There are two kinds of electric field: uniform and non-uniform electric field.

(vii)Uniform electric field will have the same direction and same magnitude at all points.

(viii)Non uniform electric field will have different directions or different magnitude or both different at all points.

5. Derive an expression for the electric field due to a point charge:

• Consider a source point charge q located at a point O.

• Another test charge qo is placed at a point P.

• It is at a distance r from the charge q. (OP =r )

• The electrostatic force experienced by the charge qo due to q is given by

Coulomb’s law.

F=k qqo/r2

But E= F/qo

+q                        -q

----------------------------->

O                           P

So, E= kq/r² 

E= q/4π€or²

Electric field acts along OP if q is positive and acts along PO if q is negative.

6. Explain the working of microwave oven.

• Microwave works on the principle of torque acting on a dipole.

• When the microwave is switched on, it produces oscillating

electromagnetic fields.

• This produces torque on the water molecules present in the food items.

• Due to this torque, the water molecules rotate very fast.

• Hence, heat energy is released.

• This heat is used to cook the food.

12th Physics Revision Test Question Paper 2022

DEPARTMENT OF SCHOOL EDUCATION, CHENGALPATTU DISTRICT 

 SECOND ASSESSMENT TEST-JANUARY -2022 REGISTER NUMBER 

PHYSICS 

 

CLASS: 12                 MAXIMUM MARKS: 70 

TIME ALLOWED: 3 HOURS 

PART – I (15 × 1 = 15)

Note: Answer all the questions. 

Choose the most appropriate answer from the given four alternatives and Write the option code and the corresponding answer. 

1. Which charge configuration produces a uniform electric field? 

(a) point charge 

(b) uniformly charged infinite line 

(c) uniformly charged infinite plane 

(d) uniformly charged spherical shell 

2. If voltage applied on a capacitor is increased from V to 2V, choose the correct conclusion. 

(a) Q remains the same, C is doubled 

(b) Q is doubled, C doubled 

(c) C remains same, Q doubled 

(d) Both Q and C remain same 

3. A sample of HCl gas is placed in a uniform electric field of magnitude 3 × 104

 N C–1. The dipole moment of each 

HCl molecule is 3.4 × 10–30 Cm. Calculate the maximum torque experienced by each HCl molecule. 

(a) 10.2 × 10+26 Nm 

(b) 10.2 × 10-26 Nm 

(c) 10.2 × 10+6 Nm 

(d) 16.2 × 10-26 Nm 

4. Resistance of a material at 200C and 400C are 45 Ω and 85 Ω respectively. Find its temperature coefficient of 

resistivity. 

(a) 0.4 per0C

(b) 0.0044 per0C 

(c) 0.044 per0C 

(d) 60.0044 per0C 

5. The filament of 50 W and 90 W bulbs are of the same length, then 

(a) 50 W filament is thicker 

(b) 90 W filament is thicker 

(c) both are of same thickness 

(d) none of these 

6. Two wires of A and B with circular cross section are made up of the same material with equal lengths. Suppose 

RA = 3 RB, then what is the ratio of radius of wire A to that of B? 

(a) 3 

(b) √3 

(c) 1/√3

(d) 1/3

7. Moving electric charge produces 

(a) both electric and magnetic fields 

(b) electric field only 

(c) magnetic field only

(d) neither of these two fields 

8. A wire of length l carrying a current I along the Y direction is kept in a magnetic field given by B= B/√3 (î+j+k) T .The magnitude of Lorentz force acting on the wire is 

(a)√(2/3) BIl

(b)√(1/3) BIl

(c)√(1/2) BIl

(d) √2 BIl

9. If the angular momentum of an electron of mass m, charge e, revolving in a circular orbit is L, then its magnetic 

moment is 

(a) eLm 

(b) eL/m

(c) eL/2m

(d) 2eL/m

10. A step-down transformer reduces the supply voltage from 220 V to 11 V and increase the current from 6 A to 100 A.

Then its efficiency is

(a) 1.2 

(b) 0.83 

(c) 0.12 

(d) 0.9

11. The self-inductance of a straight conductor is :

(a) zero 

(b) infinite 

(c) very large 

(d) very small

12. The flux linked with a coil at any instant t is given by ϕB = 10t2 - 50t + 250. The induced emf at t = 3 s is

(a) -190 V

(b) -10 V 

(c) 10 V 

(d) 190 V

13. In a series RL circuit, the resistance and inductive reactance are the same. Then the phase difference between the

voltage and current in the circuit is

(a) zero 

(b) π/4

(c) π/2

(d) π/6

14. A wire of resistance R is cut into n equal parts. These parts are then connected in parallel with each other. The

equivalent resistance of the combination is

(a) nR 

(b) R / n 

(c) n / R2

(d) R / n2

15. Two point charges (+e) and (-e) are kept inside metallic cube without touching its sides. Electric flux emerging out of the cube is

(a) zero 

(b) 2e / Ꜫo

(c) +e / Ꜫo

(d) -e / Ꜫo

PART – II (6 × 2 = 12)

Note: Answer any six questions. Question number 24 is compulsory

16. State Coulomb's law and write its vector form.

17. A 12 pF capacitor is connected to a 50 V battery. How much electrostatic energy is stored in the capacitor?

18. Define temperature co-efficient of the resistance and mention its unit

19. How can you combine three resistances, each of 4 Ω such that the total resistance of the circuit is 6 Ω?

20. State Flemming’s left hand rule

21. How will you increase the current sensitivity of a moving coil galvanometer?

22. Define Q-factor?

23. Find the instantaneous value of alternating voltage v=10sin(3 π × 104

 t ) volt at i) 0 s ii) 50 μs

24. An infinite line charge produces a field of 9 × 104 NC-1 at a distance of 2 cm. calculate the linear charge density.

 PART – III 6 × 3 = 18

Note: Answer any six questions. Question number 33 is compulsory

25. Define capacitance of the capacitor and write any three uses of the capacitor.

26. Three equal charges of 5 μC each are placed at the three vertices of an equilateral triangle of side 5 cm each. Calculate the electrostatic potential energy of the system of charges.

27. State kirchhoff’s current rule and voltage rule.

28. If the internal resistances of the cells are very low compared to external resistance R, to get the maximum advantage how the cells are supposed to connect? Deduce its expression.

29. Write the properties of magnetic field lines.

30. How is a galvanometer converted into an ammeter?- explain

31. How will you induce an emf by changing the area enclosed by the coil?

32. Mention the various energy losses in a transformer.

33. Two wires A and B of equal masses and of the same material are taken. The diameter of wire A is half the diameter of the wire B. If the resistance of wire A is 24 Ω, calculate the resistance of the wire B.

PART – IV  (5 × 5 = 25)

Note: Answer all the questions.

34. A) Calculate the electric field due to a dipole on its axial line

(OR)

 B) Derive the expression for the force on a current-carrying conductor in a magnetic field.

35. A) Obtain the condition for bridge balance in Wheatstone’s bridge.

(OR)

 B) Derive an expression for phase angle between the applied voltage and current in a series RLC circuit.

36. A) Deduce the relation for the magnetic field at a point due to an infinitely long straight conductor carrying current.

(OR)

 B) Explain the determination of the internal resistance of a cell using voltmeter.

37. A) Explain in detail the construction and working of a Van de Graaff generator.

(OR)

 B) Derive the expression for the force between two parallel, current-carrying conductors.

38. A) State Gauss law and obtain the expression for electric field due to a charged infinite plane sheet.

(OR)

 B) Deduce the expression for Self-inductance of a long solenoid