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