# Class 12 Physics Sample Paper Term 1 With Solutions Set D

Please refer to Class 12 Physics Sample Paper Term 1 With Solutions Set D provided below. The Sample Papers for Class 12 Physics have been prepared based on the latest pattern issued by CBSE. Students should practice these guess papers for class 12 Physics to gain more practice and get better marks in examinations. The Term 1 Sample Papers for Physics Standard 12 will help you to understand the type of questions which can be asked in upcoming examinations.

## Term 1 Sample Paper for Class 12 Physics With Solutions Set D

Section A

Question 1. In air the value of the total electric flux emitted from the unit positive charge is

a) ε0
b) (4πε0)−1
c) (ε0)−1
d) 4πε0

C

Question 2. 0.2 F capacitor is charged to 600 V by a battery, on removing the battery, it is connected with another parallel plate condenser of 1 F. the potential decreases to:
a) 100 V
b) 300 V
c) 600 V
d) 120 V

A

Question 3. The SI unit of current is
a) joule
b) coulomb
c) ampere
d) newton

C

Question 4. If a positive charge is displaced against the electric field in which it was situated, then
a) the intensity of the electric field decreases
b) work will be done by the electric field on the charge
c) energy of the system will decrease
d) energy will be provided by external source displacing the charge

D

Question 5. A capacitor of capacitance C = 2μF is connected as shown in the figure. If the internal resistance of the cell is 0.5Ω , the charge on the capacitor plates is

a) 6  μC
b) 2  μC
c) zero
d) 4  μC

D

Question 6. The specific resistance of a conductor increases with:
a) decrease in cross-sectional area
b) increase in temperature
c) decrease in length
d) increase in cross-sectional area

B

Question 7. On a cylindrical rod two coils are wound one above the other. What is the coefficient of mutual inductance if the inductance of each coil is 0.1H?
a) 0.15H
b) 0.05H
c) 0.20H
d) 0.10H

D

Question 8. At a point on the right bisector of a magnetic dipole, the magnetic:
a) field varies as r3
b) potential is zero at all points on the right bisector
c) field is perpendicular to the axis of dipole
d) potential varies as 1/r2

B

Question 9. If two coils of inductances L1 and L2are linked such that their mutual inductance is M, then the maximum value of M is
a) L1 – L2
b) L1 + L2
c) L1 × L2
d) √L1 L2

D

Question 10. In an ac circuit an alternating voltage, e = 200√200 sin100t volts is connected to a capacitor of capacity 1μ F. The rms value of the current in the circuit is
a) 20 mA
b) 100 mA
c) 200 mA
d) 10 mA

A

Question 11. An arrangement of three parallel straight wires placed perpendicular to plane of paper carrying same current along the same direction is shown in the figure. The magnitude of force per unit length on the middle wire W is given by

D

Question 12. In the given diagram, the reading of the ammeter (when the internal resistance of the battery is zero) is:

a) 2 A
b) 5/3
c) 10/9 A
d) 40/29 A

A

Question 13. Expression for the magnetic energy stored in a solenoid in terms of magnetic field B, area A and length l of the solenoid is

C

Question 14. For high frequency, capacitor offers
a) Less resistance
b) More resistance
c) None of these
d) Zero resistance

A

Question 15. Three point charges +q, -2q and +q are placed at points (x = 0, y = a, z = 0), (x = 0, y = 0, z = 0) and (x = a, y = 0, z = 0) and (x = a, y = 0, z = 0) respectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are
a) √2 qa along the line joining the points (x = 0, y = 0, z = 0) and (x = a, y = a, z = 0)
b) qa along the line joining the points (x = 0, y = 0, z = 0) and (x = a, y = a, z = 0)
c) √2 qa along +y direction
d) √2 qa along +x direction

A

Question 16. The capacity of a pure capacitor is 1 farad. In DC circuit, its effective resistance will be
a) infinite
b) zero
c) 1 ohm
d) 2 ohm

A

Question 17. A magnetic field:
a) always exerts a force on a charged particle
b) exerts a force, if the charged particle is moving along the magnetic field line
c) exerts a force, if the charged particle is moving across the magnetic field line
d) never exerts a force on charged particle

C

Question 18. The voltage across the terminals of an ac power supply varies with time according to Vcosωt. The voltage amplitude is V = 45.0 V. Average potential difference between the two terminals of the power supply is
a) 35.8 V
b) 33.8 V
c) 37.8 V
d) 0 V

D

Question 19. A bar magnet having a magnetic moment of 2×104 JT-1 is free to rotate in a horizontal plane. A horizontal magnetic field B = 6×10-4 T exists in the space. The work done in taking the magnet slowly from a direction parallel to the field to a direction 60° from the field is
a) 0.6 J
b) 12 J
c) 2 J
d) 6 J

D

Question 20. Three charges, each + q, are placed at the corners of an isosceles triangle ABC of sides BC and AC, each equal to 2a. D and E are the midpoints of BC and CA The work done in taking a charge Q from D to E is:

B

Question 21. When air is replaced by a dielectric medium of dielectric constant K, the maximum force of attraction between two charges separated by a distance:
a) decreases K2 times
b) decreases K times
c) increases K times
d) remains unchanged

B

Question 22. Inductance of an inductor whose reactance is 120 Ω at 80.0 Hz is
a) 0.239 H
b) 0.209 H
c) 0.199 H
d) 0.219 H

A

Question 23. What happens to the current in coil while accelerating a magnet inside it?
a) Increases
b) Decreases
c) Reverses
d) Remains constant

A

Question 24. The angle of dip at a place on the earth gives
a) the direction of the earth’s magnetic field
b) the horizontal component of the earth’s magnetic field
c) the location of geographic meridian
d) the vertical component of the earth’s field

A

Question 25. An electron is projected with uniform velocity along the axis of a current-carrying long solenoid. Which of the following is true?
a) The electron will continue to move with uniform velocity along the axis of the solenoid.
b) The electron path will be circular about the axis.
c) The electron will be accelerated along the axis.
d) The electron will experience a force at 45° to the axis and hence execute a helical path.

A

Section B

Question 26. A circular current loop of magnetic moment M is in an arbitrary orientation in an external magnetic field B. The work done to rotate the loop by 30° about an axis perpendicular to its
a) zero
b) MB/2
c) MB
d) √3 MB/2

A

Question 27. In bringing an electron towards another electron, the electrostatic potential energy of the system
a) decreases
b) become zero
c) remains same
d) increases

D

Question 28. If the net electric flux through a closed surface is zero, then we can infer
a) no net charge is enclosed by the surface
b) electric potential varies from point to point inside the surface
c) charge is present inside the surface
d) uniform electric field exists within the surface

A

Question 29. A series RC circuit is connected to an alternating voltage source. Consider two situations:
i. when the capacitor is air-filled
ii. when the capacitor is mica filled
Current through the resistor is i and voltage across the capacitor is V, then:
a) ia > ib
b) Va > Vb
c) Va < Vb
d) Va = Vb

B

Question 30. A thin semicircular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in the figure. The potential difference developed across the ring when its speed is v, is

a) zero
b) rBv and R is at higher potential
c) 2rBv and R is at higher potential
d) Bvπr2/2 and P is at higher potential

C

Question 31. Which of the following is most suitable for the core of the electromagnets?
a) Cu-Ni alloy
b) Soft iron
c) Steel
d) Air

B

Question 32. For MRI, a patient is slowly pushed in a time of 10 s within the coils of the magnet where magnetic field is B = 2.0 T. If the patient’s trunk is 0.8 m in circumference, the induced emf around the patient’s trunk is
a) 10.18×10-3V
b) 10.18×10-2V
c) 1.51×10-2V
d) 9.66×102V

A

Question 33. A potentiometer circuit has been set up for finding the internal resistance of a given cell.The main battery, used across the potentiometer wire, has an emf of 2.0 V and a negligible
internal resistance. The potentiometer wire itself is 10 m long. When the resistance R, connected across the given cell, has values of
i. infinity
ii. 9.5
the balancing lengths, on the potentiometer wire are found to be 3 and 2.85 m, respectively.
The value of internal resistance of the cell is:
a) 0.95 Ω
b) 0.75 Ω
c) 0.25 Ω
d) 0.5 Ω

D

Question 34. Two spherical conductors each of capacity C are charged to potential V and -V. These are then connected by means of a fine wire. The loss of energy is:
a) Zero
b) 2CV2
c) 1/2CV2
d) CV2

D

Question 35. Potentiometer measures the potential difference more accurately than a voltmeter, because
a) It has a wire of low resistance.
b) It draws a heavy current from external circuit.
c) It does not draw current from external circuit.
d) It has a wire of high resistance.

C

Question 36. What is the value of inductance L for which the current is maximum in a series LCR-circuit with C = 10 F and ω= 1000 s-1?
a) 100 mH
b) cannot be calculated unless R is known
c) 10 mH
d) 1 mH

A

Question 37. An inductor may store energy in
a) its magnetic field
b) its electric field
c) both in electric and magnetic fields
d) its coils

A

Question 38. The main use of studying a hysteresis curve for a given material is to estimate the
a) voltage loss
b) hysteresis loss
c) current loss
d) power loss

B

Question 39. An LRC series circuit has phase angle 31.5°. The voltage amplitude of the source is 90.0 V.
Voltage amplitude across the resistor is
a) 68.7 V
b) 76.7 V
c) 74.7 V
d) 70.7 V

B

Question 40. The dimension of electrical resistance is:
a) [ML2T-3A1]
b) [ML2T-3A-2]
c) [ML3T-3A-2]
d) [ML2T-3A-1]

B

Question 41. The power dissipated in the circuit shown in the figure is 30 watts. The value of R is:

a) 10 Ω
b) 30 Ω
c) 15 Ω
d) 20 Ω

A

Question 42. Two infinitely long parallel conducting plates having surface charge densities +σ and -σ respectively are separated by a small distance. The medium between the plates is a vacuum. If εis the dielectric permittivity of vacuum, then the electric field in the region between the plates is

B

Question 43. The magnetic field at the centre of a current-carrying circular loop having 1 A current and number of turns one will be (radius of the loop is 1 m):
a) 2μ0
b) μ0/4
c) μ0/2
d) 4μo

C

Question 44. A Rowland ring of mean radius 15 cm has 3500 turns of wire wound on a ferromagnetic core of relative permeability 800. What is the magnetic field B in the core for a magnetising current of 1.2A?
a) 3.48 T
b) 5.48 T
c) 4.08 T
d) 4.48 T

D

Question 45. Assertion (A): Electric potential and electric potential energy are different quantities.
Reason (R): For a system of positive test charge and point charge electric potential energy = electric potential.
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true but R is not the correct explanation of A.
c) A is true but R is false.
d) A is false but R is true.

C

Question 46. Assertion (A): A disc-shaped magnet deviates above a superconducting material that has been cooled by liquid nitrogen.
Reason (R): Superconductors repel a magnet.
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true but R is not the correct explanation of A.
c) A is true but R is false.
d) A is false but R is true.

A

Question 47. Assertion (A): Magnetic flux can produce induced e.m.f.
Reason (R): Faraday established induced e.m.f. experimentally.
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true but R is not the correct explanation of A.
c) A is true but R is false.
d) A is false but R is true.

D

Question 48. Assertion (A): An alternating current does not show any magnetic effect.
Reason (R): Alternating current varies with time.
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true but R is not the correct explanation of A.
c) A is true but R is false.
d) A is false but R is true.

B

Question 49. Assertion (A): The tyres of aircraft are slightly conducting.
Reason (R): If a conductor is connected to ground, the extra charge induced on conductor will flow to ground.
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true but R is not the correct explanation of A.
c) A is true but R is false.
d) A is false but R is true.

B

Section C

Question 50. A gang capacitor is formed by interlocking a number of plates as shown in the figure. The distance between the consecutive plates is 0.885 cm and the overlapping area of the plates is 5 cm2. The capacity of the unit is

a) 12.72 pF
b) 4 pF
c) 6.36 pF
d) 1.06 pF

B

Question 51. A cylindrical conductor is placed near another positively charged conductor. The net charge acquired by the cylindrical conductor will be
a) either positive or negative
b) zero
c) positive only
d) negative only

B

Question are based on the given text. Read the text carefully and answer the questions:

Potentiometer is an apparatus used for measuring the emf of a cell or potential difference between two points in an electrical circuit accurately. It is also used to determine the internal resistance of a primary cell. The potentiometer is based on the principle that, if V is the potential difference across any portion of the wire of length l and resistance R, then V l or V = kl where k is the potential gradient. Thus, potential difference across any portion of potentiometer wire is directly proportional to length of the wire of that portion. The potentiometer wire must be uniform. The resistance of the potentiometer wire should be high.

Question 52. Which one of the following is true about potentiometer?
a) It measures the emf of a cell very accurately.
b) Its sensitivity is low.
c) It is based on deflection method.
d) none of these

A

Question 53. A current of 1.0 mA is flowing through a potentiometer wire of length 4 cm and of resistance 4 . The potential gradient of the potentiometer wire is
a) 10-3 Vm-1
b) 10-5 Vm-2
c) 4 10-3 V m-1
d) 2 10-3 V m-1

A

Question 54. Sensitivity of a potentiometer can be increased by
a) decreasing potential gradient along the wire
b) increasing current through the wire
c) decreasing current through the wire
d) increasing potential gradient along the wire