# CBSE Class 12 Physics Term 1 Sample Paper Set B

See below CBSE Class 12 Physics Term 1 Sample Paper Set B with solutions. We have provided CBSE Sample Papers for Class 12 Physics as per the latest paper pattern issued by CBSE for the current academic year. All sample papers provided by our Class 12 Physics teachers are with answers. You can see the sample paper given below and use them for more practice for Class 12 Physics examination.

## CBSE Sample Paper for Class 12 Physics Term 1 Set B

Section – A

This section consists of 25 multiple choice questions with overall choice to attempt any 20 questions. In case more than desirable number of questions are attempted, ONLY first 20 will be considered for evaluation.

Q. 1. When an uncharged conducting sphere is brought near a charged conducting sphere, how the charge on conducting sphere be affected?
(A) increased
(B) decreased
(C) remain same
(D) zero

C

Q. 2. On-going away from a point charge as well as dipole, electric field due to dipole decreases with the ___________ rate as compare to point charge?
(A) same
(B) rapid
(C) slow
(D) None of these

B

Q. 3. Two metallic spheres of radii 1 cm and 3 cm are given charges of –1 × 10–2 C and 5 × 10–2 C, respectively. If these are connected by a conducting wire, the final charge on the bigger sphere is :
(A) 3 × 10–2 C
(B) 4 × 10–2 C
(C) 1 × 10–2 C
(D) 2 × 10–2 C

A

Q. 4. Which one of the following does not obey inverse square law?
(A) electric field due to a point charge
(B) electric potential due to a dipole
(C) electric potential due to a point charge
(D) electric force between two charged particles.

C

Q. 5. An electron and a proton are accelerated with the same potential. Which one of them higher velocity
(A) electron
(B) proton
(C) both have same velocity
(D) velocity will be zero

A

Q. 6. Dielectric constant in terms of capacitance of capacitor

A

Q. 7. When the plates of a charged parallel-plate capacitor are brought closer, the potential difference between the plates
(A) decreases
(B) increases
(C) remain same
(D) becomes zero

A

Q. 8. Three concentric spherical shells have radii a, b and c (a < b < c) and have surface charge densities σ, – σ and σ respectively. If VA, VB and VC denote the potentials of the three shells, then for c = a + b, we have :
(A) VC = VB ≠ VA
(B) VC ≠ VB ≠ VA
(C) VC = VB = VA
(D) VA = VC ≠ VB

D

Q. 9. When Ohm’s law is not obeyed in a conductor
(A) if temperature changes
(B) if conductor is under any strain
(C) both (A) and (B)
(D) none of these.

C

Q. 10. Specific resistance of a wire is defined as
(A) L/RA
(B) RA/L
(C) A/RL
(D) RL/A

B

Q. 11. In any network of wires carrying current, the algebraic sum of all current at node is equal to
(A) sum of all incoming currents
(B) sum of all outgoing currents
(C) zero
(D) infinite

C

Q. 12. A bar magnet is cut into two equal parts by a plane parallel to the magnetic axis. Which physical quantities remain unchanged?
(A) magnetic moment
(B) pole strength
(C) intensity of magnetization
(D) none of these

C

Q. 13. Direction of magnetic dipole moment
(A) north to south
(B) south to north
(C) east to west
(D) west to east

B

Q. 14. A moving conductor coil produced an induced e.m.f., this statement is according to which law
(A) Coulomb’s law
(C) Lenz’s law
(D) Ampere’s law

B

Q. 15. A cylindrical bar magnet is kept along the axis of circular coil. On rotating a magnet about its axis, the coil will have induced
(A) a current
(B) an e.m.f.
(C) both (A) and (B)
(D) no current

D

Q. 16. Production of induced e.m.f. in a coil due to the change of current in the same coil is
(A) self-induction
(B) mutual-induction
(C) dynamo
(D) none of these

A

Q. 17. Direction of induced current in a wire in a magnetic field is given by
(A) Fleming’s left-hand rule
(B) Fleming’s right-hand rule
(C) right-hand clasp rule
(D) Ampere’s rule

B

Q. 18. There is an electric field E in X-direction. If the work done on moving a charge 0.2 C through a distance of 2 m along a line making an angle 60° with the X-axis is 4.0, what is the value of E :
(A) √3 N/C
(B) 4 N/C
(C) 5 N/C
(D) 20 N/C

D

Q. 19. Magnetic needle is kept in a non-uniform magnetic field experience
(A) a force as well as a torque
(B) a torque but not a force
(C) a force and a torque
(D) a force but not a torque

A

Q. 20. A ferromagnetic substance is heated above its curie temperature. Which of the following statements is correct?
(A) Ferromagnetic domains get perfectly arranged.
(B) Ferromagnetic domains get randomly arranged.
(C) Ferromagnetic domains are not at all influenced.
(D) Ferromagnetic material transforms into diamagnetic substance.

B

Q. 21. ABC is an equilateral triangle. Charges +q are placed at each corner. The electric intensity at O will be :

C

Q. 22. Three capacitors are connected to D.C. source of 100 volts shown in the adjoining figure. If the charge accumulated on plates of C1, C2 and C3 are qa, qb, qc, qd, qe and qf respectively, then :

(A) qb + qd + qf = 100/9 C
(B) qb + qd + qf = 0
(C) qa + qc + qe=50 C
(D) qb = qd = qf

D

Q. 23. Power factor of the ac circuit varies between
(A) –1 and 0
(B) 0 to 1
(C) –1 and +1
(D) none of these

B

Q. 24. Two different wire loops are concentric and lie in the same plane. The current in the outer loop is clockwise and increase with time. The induced current in the inner loop is
(A) anti-clockwise
(B) clockwise
(C) zero
(D) in a direction depending on the ratio of loop radii

A

Q. 25. The r.m.s.value of potential difference V in the following figure is

(A) V0
(B) V0/2
(C) V0/√2
(D) V0/4

C

Section – B

This section consists of 24 multiple choice questions with overall choice to attempt any 20 questions. In case more than desirable number of questions are attempted, ONLY first 20 will be considered for evaluation.

Q. 26. Number of charges in 5 coulomb?
(A) electrons 3.125 × 1019
(B) 1
(C) 8.0 × 1019
(D) infinite

A

Q. 27. Electric flux emerging out one face of the cube, if a charge Q is placed at the centre of cube, is

C

Q. 28. The electric field in the free space between the sheets is

C

Q. 29. A parallel plate capacitor is charged to a potential difference V by a DC source and then disconnected. If the distance between the plates is doubled. Capacitance will change to ___________ of initial capacitance.
(A) Half
(B) Double
(C) remain same
(D) four times

A

Q. 30. Work done in moving a 10 μC between two points in an equipotential surface is
(A) zero
(B) 10 J
(C) 9 kJ
(D) 1 J

A

Q. 31. Three parallel plate capacitors of capacitance C1 < C2 < C3 are connected in parallel, then its equivalent capacitance of parallel combination Cp is _______ the equivalent capacitance of series combinations.
(A) smaller than
(B) greater than
(C) equal
(D) none of these

B

Q. 32. An air-filled parallel plate capacitor is charged to a potential difference 90 V and then insulated. A plastic plate is inserted between the plates covering the gap. The potential difference between the plates becomes 15 V. The dielectric constant of plastic is
(A) 2
(B) 3
(C) 6
(D) 8

C

Q. 33. In an adjoining figure are shown three capacitors C1, C2 and C3 joined to a battery. The correct condition will be (Symbols have their usual meanings) :

(A) Q1=Q2=Q3 and V1=V2=V3=V
(B) Q1=Q2+Q3 and V=V1+V2+V3
(C) Q1=Q2+Q3 and V=V1+V2
(D) Q2=Q3 and V2=V3

C

Q. 34. The amount of charge Q passed in time t through a cross-section of wire Q = 2t2 + 4t + 4. The value of current at time t = 2 sec is
(A) 8 A
(B) 10 A
(C) 6 A
(D) 12 A

D

Q. 35. In a meter bridge, the balancing length from the left end is found to be 30 cm. the value of the unknown resistance is
(A) 0.67 Ω
(B) 0.47 Ω
(C) 0.27 Ω
(D) 0.57 Ω

A

Q. 36. If an unaccelerated charged particle enters in a region having electric field and magnetic field

A

Q. 37. An electron moving with the velocity of 106 m/s enters in a magnetic field and follow the circular path having radius of 0.1 m, then the intensity of magnetic field must be
(A) 4.7 × 10–5 T
(B) 5.7 × 10–5 T
(C) 6.7 × 10–5 T
(D) 7.7 × 10–5 T

B

Q. 38. A cell is connected between the two points of a circular conductor so that I1 and I2 currents are flowing in two parts of the circular conductor of radius a. The magnetic field at the center of the loop is:

D

Q. 39. A bar magnet having magnetic moment 0.6 JT–1 is placed in a uniform magnetic field of 0.15 T. The potential energy of a magnet, when it is in stable equilibrium
(A) zero
(B) – 0.96 J
(C) -0.096 J
(D) – 9.60 J

C

Q. 40. A magnet of magnetic moment 10 C.G.S. is freely suspended in a uniform magnetic field of intensity of 0.3 units. The amount of work done in deflecting it with an angle of 60° in C.G.S. unit is
(A) 2.5
(B) 5.5
(C) 1.5
(D) 3.5

C

Q. 41. If relative permittivity of a medium is 2000. The absolute permeability in S.I. unit is
(A) 8p × 10–4
(B) 2p × 10–4
(C) 4p × 10–4
(D) p × 10–4

A

Q. 42. A magnetic field of 5 × 103 amp/m produces a magnetic flux density of 2π Tesla. The relative permeability is
(A) 10–3
(B) 103
(C) 104
(D) 10–4

B

Q. 43. Two coils have a mutual inductance of 0.002 H. The current changes in a first coil according to I = I0sin ωt where, I0 = 5A and ω = 20p radian/sec. The maximum value of e.m.f in second coil is
(A) π
(B) 0.1π
(C) 0.2π
(D) 0.3π

C

Q. 44. An AC generator of 220 V having internal resistance of 5 Ω and external resistance of 105 Ω. What is the power developed in the external resistance?
(A) 420 W
(B) 400 W
(C) 520 W
(D) 500 W

A

Given below are two statements labelled as Assertion (A) and Reason (R)

Directions: In the following questions, a statement of Assertion (A) and is followed by a statement of
Reason (R). Mark the correct choice as:
(A) Both Assertion (A) and Reason (R) are true, and Reason(R) is the correct explanation of (A).
(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
(C) Assertion (A) is true, but Reason (R) is false.
(D) Assertion (A) is false, but Reason (R) is true.

Q. 45. Assertion (A): Coulomb force on any charged particle is the vector sum of the forces experienced on that charge due to other charges.
Reason (R): Coulomb force between two charges depends on the magnitude of two-point charges and the distance between them

B

Q. 46. Assertion (A): When conducting slab is completely filled between the space of parallel plate capacitors, its capacitance becomes infinite.
Reason (R): Electric field inside a conductor is zero resulting in a zero potential difference between the plates.

A

Q. 47. Assertion (A): Voltmeter measure the emf of a cell when it is connected across the terminal of cell.
Reason (R): Terminal potential is given by V = E – ir.

B

Q. 48. Assertion (A): A compass needle when placed at Earth’s magnetic pole rotates in vertical plane.
Reason (R): The Earth has only vertical component of its magnetic field at the poles.

D

Q. 49. Assertion (A): At resonance, the current becomes minimum in a series LCR circuit.
Reason (R): At resonance, voltage and current are in same phase in a series LCR circuit.

D

Section – C

This section consists of 6 multiple choice questions with an overall choice to attempt any 5. In case more than desirable number of questions are attempted, ONLY first 5 will be considered for evaluation.

Q. 50. In the V-I graph for a given metallic wire at two different temperatures T1 and T2 are shown in figure. The relationship between T1 and T2 is

(A) T1 = T2
(B) T1 ∠ T2
(C) T1 ∠ T2
(D) none of these

C

Q. 51. The given figure represents the material which is

(A) ferrimagnetic
(B) ferromagnetic
(C) diamagnetic
(D) paramagnetic

C

CASE STUDY

Electric potential at a point is defined as the amount of work done in bringing a unit positive charge from infinity to that point.
So, electric potential = work done divided by the amount of charge moved.
Negative charges move from lower to higher potential. Positive charges move from higher to lower potential.
Charges gain energy while moving through a potential difference. If an electron is accelerated from rest through a potential difference of 1V, it gains 1 eV energy.

Q. 52. Formula of electric potential
(A) V = WQ
(B) V = W/Q
(C) W = VQ2
(D) V = WQ2

B

Q. 53. An electron is accelerated through a potential difference of 7 volts. The energy gained by an electron will be
(A) 7 erg
(B) 7 watt
(C) 7 eV
(D) 7 volt

C

Q. 54. Protons move from______ to ______ potential
(A) lower, higher
(B) higher, lower
(C) Random motion
(D) None of these