modern and space physics, sources of energy - Category wise Question and Answer Practice Test with Solutions

Question : 6

Match Column I and Column II.

a) A – 4 ; B – 2 ; C – 1 ; D – 3

b) A – 2 ; B – 1 ; C – 4 ; D – 3

c) A – 3 ; B – 4 ; C – 1 ; D – 2

d) A – 2 ; B – 4 ; C – 1 ; D – 3

Question : 7

Electromagnetic waves with frequencies greater than the critical frequency of ionosphere cannot be used for communication using sky wave propagation because:

a) The refractive index of the ionosphere becomes very low for f > $f_ c$

b) The refractive index of the ionosphere very high for f < $f_c$

c) The refractive index of the ionosphere becomes very high for f > $f_c$

d) None of the these

Question : 8

Telephony is an example of ________ mode of communication

a) broadcast

b) both (a) and (c)

c) point-to-point

d) None of these

Question : 9

Which part of the solar cooker is responsible for green house effect?

a) Mirror

b) Glass sheet

c) Coating with black colour inside the box

d) Outer cover of the solar cooker

Question : 10

Consider the following statements:

1. A geostationary satellite is at an approximate height of 10,000 km.
2. FM transmission of music is of very good quality because the atmospheric or man-made noises which are generally frequency variations can do little harm.

a) 2 only

b) 1 and 2 both

c) 1 only

d) None