નીચે આપેલા સંચારના માધ્યમ માટે યોગ્ય તરંગની પસંગી કરો 

\(A.\) ઓપ્ટિકલ ફાઈબર સંચાર	\(P.\) અલ્ટ્રાસાઉન્ડ
\(B.\) રડાર	\(Q.\) ઇન્ફ્રારેડ
\(C.\) સોનાર	\(R.\) માઇક્રો તરંગ
\(D.\) મોબાઈલ ફોન	\(S.\) રેડિયો તરંગ

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 \(2.24 \mathrm{GHz}\).