JEE Mains · Physics · STD 12 - Electromagnetic waves
- JEE Mains 2019
- Medium
- MCQ
Given below in the left column are different modes of communication using the kinds of waves given in the right column
| \(A.\) Optical Fiber Communication | \(P.\) Ultrasound |
| \(B.\) Radar | \(Q.\) Infrared Light |
| \(C.\) Sonar | \(R.\) Microwaves |
| \(D.\) Mobile Phones | \(S.\) Radio Waves |
Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(A -Q, B -S, C -P, D -R\)
Step-by-step Solution
Detailed explanation
\(Optical\, Fibre\, Communication -Infrared\, light\)
For fiber optics with glass fibers, we use light in the infrared region which has wavelengths longer than visible light, typically around \(850,1300\) and \(1550 \mathrm{nm}\). Scattering is caused by light bouncing off atoms or molecules in the glass.
\(Radar -Radiowave\)
Radar is a detection system that uses radio waves to determine the range, angle, or velocity of objects.
\(Sonar -ultrasound\)
Sonar, as used in robotics means having an ultrasonic emitter and ultrasonic receiver. There is also some sonar with a single emitter/receiver. However, they all use ultrasonic sound ways in order to sense the distance to an object.
\(Mobilephones -microwave\)
we use microwaves as a power transmitter to our mobile phones. For this, we require a sensor, a rectenna circuit and a filer on our mobile phone. The microwave is sent with the message by the transmitter using an antenna at frequency \(2.24 \mathrm{GHz}\).
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