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

1.

The dimensions ofare

(A)

(B)

(C) [L^-1T]

(D) [LT-1]

Answer: (D)

2.

The electric and the magnetic field, associated with an e.m. wave, propagating along the +z-axis, can be represented by

(A)

(B)

(C)

(D)

Answer: (B)

3.

The maximum height attained by a projectile when thrown at an angle q with the horizontal is found to be half the horizontal range. Then q =

(A)  Tan^-1

(B)

(C)

(D) Tan^-12

Answer: (D)

4.

The moment of inertia of a thin uniform rod of mass M and length L about an axis passing through its midpoint and perpendicular to its length is I₀. Its moment of inertia about an axis passing through one of its ends and perpendicular to its length is

(A) I₀ + ML²

(B)

(C)

(D) I₀ + 2ML²

Answer: (C)

5.

The ratio of the velocity of sound m hydrogen  to that in helium  at the

same temperature is

(A)

(B)

(C)

(D)

Answer: (B)

6.

Two equal forces (P each) act at a point inclined to each other at an angle of 120°. The magnitude of their resultant is _______.

(A) P

(B) 2 P

(C)

(D)

Answer: (A)

7.

Two waves are represented by the equations y₁ = asin(wt + kx + 0.57)m and y2 = acos(wt + kx)m, where x is in meter and t in s. The phase difference between them is

(A) 0.57 radian

(B) 1.0 radian

(C) 1.25 radian

(D) 1.57 radian

Answer: (B)

8.

With what velocity should an observer approach a stationary sound source so that the apparent frequency of sound should appear double the actual frequency? (v is velocity of sound).

(A)

(B) 3

(C) 2

(D)

Answer: (D)

9.

When the angle of incidence is 60° on the surface of a glass slab, it is found that the reflected ray is completely polarised. The velocity of light in glass is

(A) 3 ´ 10⁸ ms^-1

(B) 2 ´ 10⁸ ms^-1

(C)  ´ 10⁸ ms^-1

(D) ´ 10⁸ ms^-1

Answer: (C)

10.

A missile is fired for maximum range with an initial velocity of 20 m/s. If g = 10

m /s², the range of the missile is

(A) 20 m

(B) 40 m

(C) 50 m

(D) 60 m

Answer: (B)