Virtual lab

MOSFET

1.The drain current of a MOSFET is directly proportional to the Vgs applied only when the device is biased in

a) Saturation region

b) Triode region

c) Cut-off region

d) None of the above

2.Which of the following statement is TRUE concerning the threshold voltage (Vt) of a MOSFET?

a) Vt increases when reverse body bias increases

b) Vt decreases when reverse body bias increases

c) Channel in pMOS transistor is formed when the gate voltage is higher than Vt

d) Channel in nMOS transistor is formed when the gate voltage is lower than Vt

3. An nMOS transistor in 180nm technology has Vdd=1.8V, Vtn=0.5V, Vgs=3V. The transistor is in saturation when

a) Vds=0

b) Vds is lower than 2.5V

c) Vds is greater than 2.5V

d) Independent of Vds

4. Which of the following describes the construction of a MOSFET?

a) The gate is formed by a reverse-biased junction

b) The gate is separated from the channel with a thin insulating layer

c) The source is separated from the drain by a thin insulating later

d) The source is formed by depositing metal on silicon

5. Which of the following is NOT TRUE in saturation mode of operation in a long channel MOSFET?

a) The effective channel length of the device decreases with increase in Vds

b) Depletion width at the drain junction increases with Vds

c) Threshold voltage varies with increase in Vds

d) Square dependency of drain current with respect to Vgs

Shakshat Virtual Lab