Modern Physics 7 Question 75

5. Given below in the left column are different modes of communication using the kinds of waves given in the right column.

A. Optical fibre communication P. Ultrasound
B. Radar Q. Infrared light
C. Sonar R. Microwaves
D. Mobile phones S. Radio waves

From the options given below, find the most appropriate match between entries in the left and the right column.

(Main 2019, 10 April I)

(a) A-Q, B-S, C-R, D-P

(b) A-S, B-Q, C-R, D-P

(c) A-Q, B-S, C-P, D-R

(d) A-R, B-P, C-S, D-Q

Show Answer

Solution:

  1. In optical fibre communication, infrared light is used to transmit information from one point to another.

RADAR (Radio detection and ranging) is a detection system that uses radio waves to determine range, angle or velocity of objects.

SONAR (Sound navigation and ranging) is also a detection system that uses ultrasound to detect under water objects, submarines, etc.

Mobile phone is a portable telephone that can make and receive calls, which make use of microwave.

$\therefore$ Correct sequence is

$$ A \rightarrow Q, B \rightarrow S, C \rightarrow P \text { and } D \rightarrow R $$



NCERT Chapter Video Solution

Dual Pane