Test: MOSFET

QUESTION: 1

The MOSFET combines the areas of _ & ___

A.
field effect & MOS technology
B.
semiconductor & TTL
C.
mos technology & CMOS technology
D.
none of the mentioned

Solution:

It is an enhancement of the FET devices (field effect) using MOS technology.

QUESTION: 2

Which of the following terminals does not belong to the MOSFET?

A.
Drain
B.
Gate
C.
Base
D.
Source

Solution:

MOSFET is a three terminal device D, G & S.

QUESTION: 3

Choose the correct statement

A.
MOSFET is a uncontrolled device
B.
MOSFET is a voltage controlled device
C.
MOSFET is a current controlled device
D.
MOSFET is a temperature controlled device

Solution:

It is a voltage controlled device.

QUESTION: 4

Choose the correct statement(s)
i) The gate circuit impedance of MOSFET is higher than that of a BJT
ii) The gate circuit impedance of MOSFET is lower than that of a BJT
iii) The MOSFET has higher switching losses than that of a BJT
iv) The MOSFET has lower switching losses than that of a BJT

A.
Both i & ii
B.
Both ii & iv
C.
Both i & iv
D.
Only ii

Solution:

MOSFET requires gate signals with lower amplitude as compared to BJTs & has lower switching losses.

QUESTION: 5

Choose the correct statement

A.
MOSFET is a unipolar, voltage controlled, two terminal device
B.
MOSFET is a bipolar, current controlled, three terminal device
C.
MOSFET is a unipolar, voltage controlled, three terminal device
D.
MOSFET is a bipolar, current controlled, two terminal device

Solution:

MOSFET is a three terminal device, Gate, source & drain. It is voltage controlled unlike the BJT & only electron current flows.

QUESTION: 6

The arrow on the symbol of MOSFET indicates

A.
that it is a N-channel MOSFET
B.
the direction of electrons
C.
the direction of conventional current flow
D.
that it is a P-channel MOSFET

Solution:

The arrow is to indicate the direction of electrons (opposite to the direction of conventional current flow).

QUESTION: 7

The controlling parameter in MOSFET is

A.
Vds
B.
Ig
C.
Vgs
D.
Is

Solution:

Correct Answer :- b

Explanation : The gate to source voltage is the controlling parameter in a MOSFET.

QUESTION: 8

In the internal structure of a MOSFET, a parasitic BJT exists between the

A.
source & gate terminals
B.
source & drain terminals
C.
drain & gate terminals
D.
there is no parasitic BJT in MOSFET

Solution:

Examine the internal structure of a MOSFET, notice the n-p-n structure between the drain & source. A p-channel MOSFET will have a p-n-p structure.

QUESTION: 9

In the transfer characteristics of a MOSFET, the threshold voltage is the measure of the

A.
minimum voltage to induce a n-channel/p-channel for conduction
B.
minimum voltage till which temperature is constant
C.
minimum voltage to turn off the device
D.
none of the above mentioned is true

Solution:

It is the minimum voltage to induce a n-channel/p-channel which will allow the device to conduct electrically through its length.

QUESTION: 10

The output characteristics of a MOSFET, is a plot of

A.
Id as a function of Vgs with Vds as a parameter
B.
Id as a function of Vds with Vgs as a parameter
C.
Ig as a function of Vgs with Vds as a parameter
D.
Ig as a function of Vds with Vgs as a parameter

Solution:

It is Id vs Vds which are plotted for different values of Vgs (gate to source voltage).

QUESTION: 11

In the output characteristics of a MOSFET with low values of Vds, the value of the on-state resistance is

A.
Vds/Ig
B.
Vds/Id
C.
0
D.
∞

Solution:

The o/p characteristics Is a plot of Id verses Vds, which for low values of Vds is almost constant. Hence, the on-state resistance is constant & the slop is its constant value.

QUESTION: 12

At turn-on the initial delay or turn on delay is the time required for the

A.
input inductance to charge to the threshold value
B.
input capacitance to charge to the threshold value
C.
input inductance to discharge to the threshold value
D.
input capacitance to discharge to the threshold value

Solution:

It is the time required for the input capacitance to charge to the threshold value, which depends on the device configuration. The device can start conducting only after this time.

QUESTION: 13

Choose the correct statement