Ray Optics and Optical Instruments — Physics STD 12 Science — Question

Why does light travel as a wave?

A 1mA beam of protons with a cross-sectional area of 0.5 sq. mm is moving with a velocity of 3  . Then charge density of beam is

(a) 6.6

(b) 6.6

(c) 6.6

(d) None of these

An electron and a proton are at a distance of 1. The moment of this dipole will be (C  X m)

(a) 1.6

(b) 1.6

(c) 3.2

(d) 3.2

A ray passes through a prism of angle 60° in minimum deviation position and suffers a deviation of 30°. What is the angle of incidence on the prism

(a) 30°

(b) 45°

(c) 60°

(d) 90°

White light is passed through a prism whose angle is 5°. If the refractive indices for rays of red and blue colour are respectively 1.64 and 1.66, the angle of deviation between the two colours will be

(a) 0.1 degree

(b) 0.2 degree

(c) 0.3 degree

(d) 0.4 degree

A charge + q is sent through a magnetic field. The force acting on it is maximum when the angle between the direction of motion of the charged particle and the magnetic field:

An electron in the n = 1 orbit of hydrogen atom is bound by 13.6 eV energy is required to ionize it is

(a) 13.6 eV

(b) 6.53 eV

(c) 5.4 eV

(d) 1.51 eV

The resistance of a galvanometer is 50 ohms and the current required to give full scale deflection is 100μA. In order to convert it into an ammeter, reading upto 10A, it is necessary to put a resistance of

(a) 5  in parallel	(b) 5  in parallel
(c)  in series	(d) 99,950  in series

The direction of the induced current in the coil can also be found by: