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Electronics and Communication Engineering - Materials and Components

Exercise : Materials and Components - Section 6
36.
The number of turns in a coil is doubled. If initial time constant is T, the new time constant is
T
2T
4T
Answer: Option
Explanation:

When N is doubled, resistance becomes twice and inductance becomes four times.

Since time constant is , time contant become twice.

37.
When a trivalent impurity is added, the semiconductor becomes
p type
n type
intrinsic
neutral
Answer: Option
Explanation:
No answer description is available. Let's discuss.
38.
Iron has a body centred cubic structure.
True
False
Answer: Option
Explanation:
No answer description is available. Let's discuss.
39.
The units of polarization of dielectric are
Cm
Answer: Option
Explanation:

Polarization P = ∈0(∈r - 1)E.

Therefore units of Polarization = .

40.
When a potential is applied across an intrinsic semiconductor, holes flow
towards positive terminal
away from positive terminal
in the external circuit only
none of the above
Answer: Option
Explanation:

Holes are positively charged and move away from positive terminal.

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