Physics Model Question Paper 7: (For Class 11 and 12 and Pre-Medical/Engineering Entrance)

1.

The dimensions of 'resistance' are same as those of _____ where h is the Planck's constant, e is the charge.

(A)

(B)

(C)

(D)

Answer: (A)

2.

The efficiency of Carnot's heat engine is 0.5 when the temperature of the source is T₁ and that of sink is T₂. The efficiency of another Carnot's heat engine is also 0.5. The temperature of source and sink of the second engine are respectively _____.

(A) T₁ + 5, T₂ - 5

(B) T₁ + 10, T₂ - 10

(C) 2T₁, 2T₂

(D) 2T₁,

Answer: (C)

3.

The equation of a simple harmonic wave is given by y = 6Sin 2p(2t - 0.1x), where x and y are in mm and t is in seconds. The phase difference between two particles 2 mm apart at any instant is

(A) 18⁰

(B) 36⁰

(C) 54⁰

(D) 72⁰

Answer: (D)

4.

The focal length of a plano convex lens is 'f' and its refractive index is 1.5. It is kept over a plane glass plate with its curved surface touching the glass plate. The gap between the lens and the glass plate is filled by a liquid. As a result, the effective focal length of the combination becomes 2f. Then the refractive index of the liquid is ______.

(A) 1.25

(B) 1.33

(C) 1.5

(D) 2

Answer: (A)

5.

The forbidden energy gap in Ge is 0.72 eV. Given, hc = 12400 eV - . The maximum wavelength of radiation that will generate an electron hole pair is ______.

(A) 17222

(B) 1722

(C) 172220

(D) 172.2

Answer: (A)

6.

The magnetic field at the centre of a circular current carrying conductor of radius r is B_c. The magnetic field on its axis at a distance r from the centre is B_a. The value of B_c : B_a will be

(A) 1 :

(B) 1 : 2

(C) 2 : 1

(D)  : 1

Answer: (C)

7.

The masses of two radioactive substances are same and their half lives are 1 year and 2 years respectively. The ratio of their activities after 6 years will be

(A) 1 : 4

(B) 1 : 2

(C) 1 : 3

(D) 1 : 6

Answer: (A)

8.

The maximum kinetic energy of emitted electrons in a photoelectric effect does not

depend upon

(A) wavelength

(B) frequency

(C) intensity

(D) work function

Answer: (C)

9.

The maximum number of possible interference maxima when slit separation is equal to 4 times the wavelength of light used in a double slit experiment is

(A)  ¥

(B) 9

(C) 8

(D) 4

Answer: (B)

10.

The most stable particle in Baryon group is

(A) neutron

(B) omega - particle

(C) proton

(D) lamda - particle

Answer: (C)