An n-channel JFET having a pinch-off voltage VP of

An n-channel JFET having a pinch-off voltage V_P of – 5V shows a transconductance g_m of 1 mA/V when the applied gate to source voltage is – 3V. Its maximum transconductance in (mA/V) will be—

Given, g_m = 1 mA/V, V_p = – 5V, V_GS = – 3V, g_mo =?

We know that g_m = g_mo		1 -	V_GS
			V_p

Where, g_mo = maximum transconductance

1 = g_mo		1 -		- 3
				- 5

or 1 = g_mo			5 - 3
			5

or g_mo =	5	= 2·5 mA/V
	2

Hence alternative (D) is the correct choice.