# The Pinch off Voltage Vp MCQ’s

This set of Electronic Devices & Circuits Multiple Choice Questions & Answers (MCQs) focuses on “The Pinch off Voltage Vp”.

1. A p-channel Ge JFET has max-half channel width 5µm and channel conductivity of 2/Ωcm, if Er = 2000cm2/Vsec, What is the value of pinch off voltage?
a) 8.21V
b) 82.1V
c) 88.21V
d) 5.2V

2. What will happen if gate voltage applied is positive to pinch off voltage?
a) Device burns
b) More current flows
c) Nothing happens
d) Current remains the same

3. What is pinch off voltage?
a) The minimum voltage required to turn on the FET
b) The maximum voltage a FET can withstand
c) Current amplification factor/voltage gain
d) The value of voltage at which the current gets pinched to zero

4. How does a FET behave when the v-I characteristics are to the left of pinch off for an n channel FET?
a) Voltage controlled resistor
b) Amplifier
c) Switch
d) Diode

5. If a FET has a pinch off voltage =-1V and ID=1mA, If Vgs=0V, What is the value of IDSS?
a) 1A
b) 1mA
c) 0A
d) 100mA

6. For a n-channel FET, what is the condition of Vgs for which the current becomes zero?
a) 0
b) 100V
c) Vp
d) Infinite

7. What is the relation between the drain current and source current once the voltage crosses pinch off?
a) ID = IS
b) ID = IS + 1.5
c) ID = 1/IS
d) IS – 2ID = 0

8. For what value of Vgs, the drain current will be 1/4th of its maximum current?
a) 0
b) 1
c) Vp
d) Vp/2

9. For a FET having IDSS=2mA Vgs=2V and Vp=-1V, What is the value of source current?
a) 9mA
b) 18mA
c) 3mA
d) 1mA

10. Find the current through gate if the FET was given with gate to source voltage =10V and drain to source voltage =20V, the pinch off voltage was -2V and ID=2mA.
a) 10mA
b) 20mA
c) 0mA
d) 2mA