# CBSE Term 1 Class 12 Physics, Board Exam 2021-22: Question Paper and Answer Key

CBSE 2021-22, Class 12 Physics board today's exam question paper. Check the answers key of the class 12 Physics (Term 1) paper.

## Class 12th CBSE Term 1, Physics Board Exam Question Paper and Answers Key 2021-22

• SUBJECT- Physics
• Term- I
• Time allowed- 90 minutes
• Maximum Marks- 40

## Q1. A negative charged object X is repelled by another charged object Y. However an object Z is attracted to object Y. Which of the following is the most possibility for the object Z?

a. positively charged only

b. negatively charged only

c. neutral or positively charged

d. neutral or negatively charged

## Q2. In an experiment three, microscopic latex spheres are sprayed into a chamber and became charged with charges +3e, +5e and -3e respectively. All the three spheres came in contact simultaneously for a moment and got separated. Which one of the following are possible values for the final charge on spheres?

a. +5e, -4e, +5e

b. +5e, +6e, -7e

c. -4e, +3.5e, +5.5e

d. +5e, -8e, +7e

a. -0.80 C

b. +0.80 C

c. +1.80 C

d. +0.20 C

## Q4. Kirchhoff’s first rule I = 0 and second rule IR = E (where the symbols have their usual meanings) are respectively based on:

a. conservation of momentum and conservation of charge

b. conservation of energy, conservation of charge

c. conservation of charge, conservation of momentums

d. conservation of charge, conservation of energy

a. 25 w

b. 30 W

c. 35 W

d. 45 W

## Q6. Which one of the following has negative temperature coefficient of resistivity?

a. metal

b. metal and semiconductor

c. semiconductor

d. metal and alloy

a. I

b. II

c. III

d. IV

## Q8. Two parallel conductors carrying 0f 3.0 A and 10.0 A are placed 2.5 cm apart in vacuum. The force per unit length between them is:

a. 6.4 x  10 power -5 N/m

b. 6.4 x 10 power -2 N/m

c. 4.6 x 10 power -4 N/m

d. 3.2 x 10 power -4 N/m

## Q9. If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a:

a. low resistance in parallel

b. low resistance in series

c. high resistance in parallel

d. high resistance in series

a. 2√2

b. 1/√2

c. √2

d. 2

a. 95mH

b. 90mH

c. 85mH

d. 75mH

a. 15/√2 A

b. 15√2 A

c. √2/15 A

d. 8 A

a. only C

b. Only L

c. L and R

d. L or C

## Q14. The electric potential V at any point (x, y, z) is given by V = 3x power 2 where x is in meters and V in volts. The electric field at the point (1 m, 0, 2m) is:

a. 6 V/m along -x axis

b. 6 V/m along +x axis

c. 1.5 V/m along -x axis

d. 1.5 V/m along +x axis

(a) 1 uF

(b) 2uF

(c) 3 uF

(d)) 4uF

(a) 1.25 x 1019

(b) 2.5 x 1018

(c) 1.25 x 1018

(d) 2.5 x 1016

(a) Erms. Irms

(b) Eo Io

(c) Eo Io/√2

(d) Zero

## Q20. A current carrying wire kept in a uniform magnetic field, will experience a maximum force when it is

(a) perpendicular to the magnetic field

(b) parallel to the magnetic field

(c) at an angle of 45° to the magnetic field

(d) at an angle of 60° to the magnetic field

(a) 5 V

(b) 20 V

(c) 25 V

(d) 65 V

## Q22. In a dc circuit the direction of current inside the battery and outside the battery respectively are –

(a) positive to negative terminal and negative to positive terminal

(b) positive to negative terminal and positive to negative terminal

(c) negative to positive terminal and positive to negative terminal

(d) negative to positive terminal and negative to positive terminal

(a) E/4

(b) 0

(c) 2E

(d) 4E

(a) 30°

(b) 45°

(c) 60°

(d) 90°

(a) 50 V

(b) 75 V

(c) 100 V

(d) 220 V

(a) a4c

(b) ⅓a3c

(c) ⅓a4c

(d) 0

a. 0

b. 2kqq0/n2

c. 2kqq0/a2

d. 1/2 kqq0/a2

## Q28. A + 3.0 nC charge Q is initially at rest at a distance of r; = 10 cm from a + 5.0 nC charge q fixed at the origin. The charge Q is moved away from q to a new position at r, = 15 cm. In this process work done by the field is

(a) 1.29 x 10-5 J

(b) 3.6 x 105 J

(c) -4.5 x 10-7J

(d) 4.5 x 10-7 J

(a) 6.0 x 104 C

(b) 5.8 x 103 J

(c) 8.64 x 106 J

(d) 1.6 x 106c

(a) mgB/l

(b) mgl/B

(c) mg/lB

(d) lB/mg

## Q31. A constant current is flowing through a solenoid. An iron rod is inserted in the solenoid along its axis. Which of the following quantities will not increase?

(a) The magnetic field at the centre

(b) The magnetic flux linked with the solenoid

(c) The rate of heating

(d) The self-inductance of the solenoid

(a) L, C and R

(b) L and C

(c) Land R

(d) R and C

(a) 3/4

(b) 4/3

(c) 8/9

(d) 9/8

(a) 5/3 v

(b) 5073 V

(c) 5.0 V

(d) 50.0 V

(a) 100 uF

(b) 127 uF

(c) 142 uF

(d) 160 uF

(a) F/7

(b) F/5

(c) F/3

(d) F/2

## Q39. Which of the following statements is correct?

(a) Magnetic field lines do not form closed loops.

(b) Magnetic field lines start from north pole and end at south pole of a magnet.

(c) The tangent at a point on a magnetic field line represents the direction of the magnetic field at that point.

(d) Two magnetic field lines may intersect each other.

(a) 3R Ω

(b) (3/2)R Ω

(c) 2R Ω

(d) (2/3) RΩ

## Q41. A bar magnet has magnetic dipole moment M. Its initial position is parallel to the direction of uniform magnetic field B. In this position, the magnitudes of torque and force acting on it respectively are –

(a) 0 and MB

(b) MB and MB

(c) 0 and 0

(d) |M X B| and 0

(a) 0.1 A

(b) 0.4 A

(c) 0.6 A

(d) 0.8 A

## Q44. The core of a transformer is laminated to reduce the effect of:

(a) flux leakage

(b) copper loss

(c) hysteresis loss

(d) eddy current

## Reason (R): On a negative charge a force acts in the direction of the electric field

(a) Both (A) and (R) are true and (R) is correct explanation of (A)

(b) Both (A) and (R) are true and (R) is  not correct explanation of (A)

(c) (A) is true, but (R) is false

(d) (A) is false and (R) is also false

## Reason (R): Magnetic monopoles do not exist

(a) Both (A) and (R) are true and (R) is correct explanation of (A)

(b) Both (A) and (R) are true and (R) is  not correct explanation of (A)

(c) (A) is true, but (R) is false

(d) (A) is false and (R) is also false

## Reason (R): The magnetic moment of a current carrying loop is directly proportional to the area of the loop

(a) Both (A) and (R) are true and (R) is correct explanation of (A)

(b) Both (A) and (R) are true and (R) is  not correct explanation of (A)

(c) (A) is true, but (R) is false

(d) (A) is false and (R) is also false

## Reason (R): To increase the range of an ammeter additional shunt is added in series to it

(a) Both (A) and (R) are true and (R) is correct explanation of (A)

(b) Both (A) and (R) are true and (R) is  not correct explanation of (A)

(c) (A) is true, but (R) is false

(d) (A) is false and (R) is also false

## Reason (R): A transformer works only in one direction

(a) Both (A) and (R) are true and (R) is correct explanation of (A)

(b) Both (A) and (R) are true and (R) is  not correct explanation of (A)

(c) (A) is true, but (R) is false

(d) (A) is false and (R) is also false

(a) spheres

(b) planes

(c) ellipsoids

(d) parabolas

(a)

(b)

(c)

(d)

(a) b, c, d

(b) f, h, j

(c) d, e, f

(d) a, b, j

(a) 1 A

(b) 1/3 A

(c) 1/2 A

(d) 2/3 A

(a) 2 W

(b) 2.5 W

(c) 3 W

(d) 4.5 W

(a) 1.5 V

(b) 2 V

(c) 2.5 V

(d) 3 V