Physics Model Question Paper 6: (For Class 11 and 12 and Pre-Medical/Engineering Entrance)

1.

ln which of the processes, does the internal energy of the system remain constant?

(A) Adiabatic

(B) Isochoric

(C) Isobaric

(D) Isothermal

Answer: (D)

2.

Magnetic field at the centre of a circular coil of radius R due to current I flowing through it is B. The magnetic Held at a point along the axis at distance R from the centre is ______.

(A)

(B)

(C)

(D)  

Answer: (A)

3.

Maximum diffraction takes place in a given slit for

(A) g- rays

(B) ultraviolet light

(C) infrared light

(D) radio waves

Answer: (D)

4.

On bombarding U²³⁵ by slow neutron, 200 MeV energy is released. If the power output of atomic reactor is 1.6 MW, then the rate of fission will be

(A) 5 ´ 10²²/s

(B) 5 ´ 10¹⁶/s

(C) 8 ´ 10¹⁶/s

(D) 20 ´ 10¹⁶/s

Answer: (B)

5.

Pick out the correct statement from the following :

(A) pu²³⁹ is not suitable for a fission reaction.

(B) For stable nucleus, the specific binding energy is low.

(C) Energy released per unit mass of the reactant is less in case of fusion reaction.

(D) Packing fraction may be positive or may be negative

Answer: (D)

6.

Pick out the statement which is NOT correct.

(A) Width of the depletion region increases as the forward bias voltage increases in case of a N—P junction diode.

(B) In a forward bias condition, the diode heavily conducts.

(C) At a low temperature, the resistance of a semiconductor is very high.

(D) Movement of holes is restricted to the valence band only.

Answer: (A)

7.

Red light of wavelength 625 nm is incident normally on an optical diffraction grating with 2 ´ 10⁵ lines/m. Including central principal maxima, how many maxima may be observed on a screen which is far from the grating?

(A) 8

(B) 16

(C) 15

(D) 17

Answer: (D)

8.

Solar spectrum is an example for

(A) line emission spectrum

(B) continuous emission spectrum

(C) band absorption spectrum

(D) line absorption spectrum

Answer: (D)

9.

The charges Q, + q and + q are placed at the vertices of an equilateral triangle of side l. If the net electrostatic potential energy of the system is zero, then Q is equal to

(A)

(B) -q

(C)

(D) zero

Answer: (A)

10.

The de-Broglie wavelength of the electron in the ground state of the hydrogen atom is _____ (radius of the first orbit of hydrogen atom = 0.53 A).

(A) 1.06

(B) 0.53

(C) 1.67

(D) 3.33

Answer: (D)