1-V characteristics of four devices are shown in figure.

Identify devices that can be used for modulation

Options

A. (i) and (iii)
B. Only (iii)
C. (iii) and some regions of (iv)
D. All the devices can be used

Answer

C

Explanation

Here, (i) represents ideal modulation related to triode valve for linear plate modulation.
(ii) represents square law diode modulation.
(iii) represents constant current source.
(iv) represents part of it as square law modulation. Thus, for modulation (iii) and some regions of (iv) can be used.