a) donor doped
b) acceptor doped
c) all of the mentioned
d) none of the mentioned
Answer: a
nMOS is acceptor doped and pMOS is donor doped devices. Acceptor doped forms p-type region and donor doped forms n-type region.
12. Inversion layer in enhancement mode consists of excess of ____________
a) positive carriers
b) negative carriers
c) both in equal quantity
d) neutral carriers
Answer: b
The inversion layer in enhancement mode consists of the excess of negative carriers that is electrons.
13. What is the condition for the linear region?
a) Vgs lesser than Vt
b) Vgs greater than Vt
c) Vds lesser than Vgs
d) Vds greater than Vgs
Answer: b
The condition for the linear region is Vgs > Vt. The power of MOS in the linear region is less. It is a power dissipating region.
14. As source drain voltage increases, channel depth ____________
a) increases
b) decreases
c) logarithmically increases
d) exponentially increases
Answer: b
As source-drain voltage Vds increase, the channel depth at the drain end decreases.
15. MOS transistors consist of which of the following?
a) semiconductor layer
b) metal layer
c) layer of silicon-di-oxide
d) all of the mentioned
Answer: d
MOS transistors are formed as a sandwich consisting of a semiconductor layer, a silicon-di-oxide layer, and a metal layer.
16. In MOS transistors _______________ is used for their gate.
a) metal
b) silicon-di-oxide
c) polysilicon
d) gallium
Answer: c
In MOS transistors, polycrystalline silicon is used for their gate region instead of metal. Polysilicon gates have replaced all other older devices.
17. The gate region consists of ____________
a) insulating layer
b) conducting layer
c) lower metal layer
d) p type layer
Answer: b
The gate region is a sandwich consisting of the semiconductor layer, an insulating layer and an upper metal layer.
18. Electrical charge flows from ____________
a) source to drain
b) drain to source
c) source to ground
d) source to gate
Answer: a
Electrical charge or current flows from source to drain depending on the charge applied to the gate region.
19. Source in MOS transistors is doped with ______ material.
a) n-type
b) p-type
c) n & p-type
d) none of the mentioned
Answer: a
Source and drain in the MOS transistors are doped with N-type material and the substrate is doped with p-type material.
20. In N channel MOSFET which is the more negative of the elements?
a) source
b) gate
c) drain
d) source and drain
Answer: a
In N channel MOSFET, the source is the more negative of the elements and in the case of P channel MOSFET, it is the more positive of the elements.
