1. According to body effect, substrate is biased with respect to ___________
a) source
b) drain
c) gate
d) Vss
Explanation: According to body effect, the substrate is biased with respect to the source. Body effect can be seen as a change in the threshold voltage
2. Increasing Vsb _______ the threshold voltage.
a) does not effect
b) decreases
c) increases
d) exponentially increases
Explanation:Increasing the substrate bias voltage Vsb, increases the threshold voltage because it depletes the channel of charge carriers.
3. Transconductance gives the relationship between ___________
a) input current and output voltage
b) output current and input voltage
c) input current and input voltage
d) output current and output voltage
Explanation:Transconductance expresses the relationship between output current Ids and input voltage Vgs
4. Transconductance can be increased by ___________
a) decreasing the width
b) increasing the width
c) increasing the length
d) decreasing the length
Explanation: Transconductance gm of a MOS device can be increased by increasing its width and it does not depend on length
5. Increasing the transconductance ___________
a) increases input capacitance
b) decreasing area occupied
c) decreasing input capacitance
d) decrease in output capacitance
Explanation: Increasing the transconductance gm results in an increase in input capacitance and area occupied as it is directly proportional
6. Ids is _______ to length L of the channel.
a) directly proportional
b) inversely proportional
c) not related
d) logarithmically related
Explanation: Ids is inversely proportional to the length L of the channel and using this relationship strong dependence of output conductance on channel length can be demonstrated
7. Switching speed of a MOS device depends on ___________
a) gate voltage above a threshold
b) carrier mobility
c) length channel
d) all of the mentioned
Explanation: Switching speed of a MOS device depends on gate voltage above a threshold and on carrier mobility and inversely as the square of channel length
8. A fast circuit requires ___________
a) high gm
b) low gm
c) does not depend on gm
d) low cost
Explanation: A fast circuit requires gm as high as possible as the switching speed depends on gate voltage above threshold and on carrier mobility and inversely to square of channel length.
9. Surface mobility depends on ___________
a) effective drain voltage
b) effective gate voltage
c) channel length
d) effective source voltage
Explanation: Surface mobility is dependent on the effective gate voltage (Vgs-Vt). Electron mobility on oriented n-type inversion layer surface is larger than that on an oriented surface.
10. What is a MOS transistor?
a) minority carrier device
b) majority carrier device
c) majority & minority carrier device
d) none of the mentioned
Explanation: MOS transistor is a majority carrier device, in which current in a conducting channel between the source and drain is modulated by a voltage