RSMSSB JSA Ballistic 2019 Paper

RSMSSB Junior Scientific Assistant Ballistic Paper 2019
Date of Exam – 21st Sept 2019

The coherent sources whose intensity ratio is 9 : 1 produce interference fringe pattern. The ratio of maximum to minimum intensity in fringe pattern is
(a) 2 : 1
(b) 4 : 1
(c) 9 : 1
(d) 3 : 1

The observed length of one meter stick moving with speed equal to half of speed of light is
(a) 0.87 m
(b) 1.87 m
(c) 0.50 m
(d) 1.50 m

If a charge ‘q’ is placed at the centre of the line joining two equal charges of magnitude ‘Q’ such that the system is in equilibrium, the value of ‘q’ is
(a) Q/2
(b) – Q/2
(c) Q/4
(d) – Q/4

When forward bias is applied to a p-n junctions, the width of depletion region
(a) increases
(b) remains same
(c) decreases
(d) may increase or decrease

Which of the following statements is not true about mean free path of a gas molecule?
(a) Mean free path is inversely proportional to the density of gas
(b) Mean free path is inversely proportional to the pressure of gas
(c) Mean free path is inversely proportional to the square of the molecular diameter
(d) Mean free path is inversely proportional to the absolute temperature of the gas

In photo electric effect, the kinetic energy of electron emitted from the metal surface depends upon
(a) intensity of incident light
(b) frequency of incident light
(c) velocity of incident light
(d) both intensity and velocity of incident light

The fundamental frquency of a stretched string is proportional to
(a) inverse of the length
(b) its dimeter
(c) inverse of the tension
(d) its mass

According to Hookes law of elasticity, if stress is increased, then the ratio of stress to strain
(a) increases
(b) decreases
(c) becomes zero
(d) remains constant

If H is a subgroup of G and N is normal subgroup of G, then H intersection N is a normal subgroup of
(a) G
(b) H
(c) N
(d) H and N

The image of the origin w.r.t the plane x+y+z=1 is
(a) (1,1,1)
(b) (1/3,1/3,1/3)
(c) (-1/3, -1/3, – 1/3)
(d) (2/3, 2/3, 2/3)