Question

I-V characteristics of four devices are shown in Figures.

(i)	(ii)	(iii)	(iv)

Identify devices that can be used for modulation.

विकल्प

• 'i’ and ‘iii’.

• only ‘iii’.

• ‘ii’ and some regions of ‘iv’.

• All the devices can be used.

Answer 1

‘ii’ and some regions of ‘iv’.

Explanation:

A square law modulator is a device which can produce modulated waves by the application of the message signal and the carrier wave.

A square law modulator is used for modulation purposes. Characteristics shown by (i) and (iii) correspond to linear devices.

And by (ii) corresponds to the square law device which shows non-linear relations. Some parts of (iv) also follow square law.

Hence, (ii) and (iv) can be used for modulation.