Electrical Properties of MOS and BiCMOS Circuits MCQ Quiz – Objective Question with Answer for Electrical Properties of MOS and BiCMOS Circuits MCQ MCQ
A. high gm
B. low gm
C. does not depend on gm
D. low cost
Answer: A
A fast circuit requires gm as high as possible as the switching speed depends on gate voltage above the threshold and on carrier mobility and inversely to the square of channel length.
22. Surface mobility depends on ___________
A. effective drain voltage
B. effective gate voltage
C. channel length
D. effective source voltage
Answer: B
Surface mobility is dependent on the effective gate voltage (Vgs-Vt). Electron mobility on an oriented n-type inversion layer surface is larger than that on an oriented surface.
23. What is a MOS transistor?
A. minority carrier device
B. majority carrier device
C. majority & minority carrier device
D. none of the mentioned
Answer: B
MOS transistor is a majority carrier device, in which current in a conducting channel between the source and drain is modulated by a voltage.
24. The MOS transistor is non conducting when?
A. zero source bias
B. zero threshold voltage
C. zero gate bias
D. zero drain bias
Answer: C
The MOS transistor normally is at cut-off or becomes non-conducting with zero gate bias (gate voltage-source voltage).
25. Inverters are essential for ________
A. NAND gates
B. NOR gates
C. sequential circuits
D. all of the mentioned
Answer: D
Inverters are needed for restoring logic levels for NAND and NOR gates, and sequential and memory circuits.
26. In basic inverter circuit _____________ is connected to ground.
A. source
B. gates
C. drain
D. resistance
Answer: A
A basic inverter circuit consists of the transistor with a source connected to the ground and a load resistor connected from the drain to the positive supply rail Vdd.
27. In inverter circuit ________ transistors are used as the load.
A. enhancement mode
B. depletion-mode
C. all of the mentioned
D. none of the mentioned
Answer: B
Depletion mode transistors are preferred to be used as a load in inverter circuits as it occupies a lesser area and is produced on the silicon substrate, unlike resistors.
28. For the depletion-mode transistor, the gate should be connected to ________
A. source
B. drain
C. ground
D. positive voltage rail
Answer: A
For the depletion-mode transistor, the gate is connected to the source so it is always on and only the characteristic curve Vgs=0 is relevant.
29. In nMOS inverter configuration depletion mode device is called as ________
A. pull up
B. pull down
C. all of the mentioned
D. none of the mentioned
Answer: A
In nMOS inverter configuration, depletion mode devices are called pull up and enhancement mode devices are called pull-down transistors.
30. What is the ratio of Zp.u/Zp.d?
A. 1/4
B. 4/1
C. 1/2
D. 2/1
Answer: B
The ratio of Zp.u/Zp.d, where Z is determined by the length to width ratio of the transistor, is given by 4/1.
