Eduprobe
Question:
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
A−S,B−Q,C−R,D−P
A−R,B−P,C−S,D−Q
A−Q,B−S,C−R,D−P
A−Q,B−S,C−P,D−R
Solution:
Correct option is D. A−Q,B−S,C−P,D−R
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 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.
Mobile phones−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 GHz.