Electronics and Communication Engineering - Electronic Devices and Circuits
Exercise :: Electronic Devices and Circuits - Section 14
| 1. |
The ratio of impurity atoms to intrinsic semiconductor atoms in an extrinsic semiconductor is about. |
| A. |
1 : 10 | | B. |
1 : 1000 | | C. |
1 : 100000 | | D. |
1 : 108 |
Answer: Option D
Explanation:
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| 2. |
To ensure that a zener diode does not get destroyed |
| A. |
the applied voltage should not exceed breakdown voltage | | B. |
the current should not exceed rated current | | C. |
the current should be less than magnitude of barrier potential | | D. |
both (a) and (b) |
Answer: Option B
Explanation:
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| 3. |
SCR turns of from conducting state to blocking state on |
| A. |
reducing gate current | | B. |
reversing gate voltage | | C. |
reducing anode current below holding current value | | D. |
applying ac to the gate |
Answer: Option C
Explanation:
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| 4. |
The kinetic energy of free electrons in a metal is (where k is the de-Broglie wave number of the electron) |
| A. |
inversely proportional to k | | B. |
inversely proportional to square of k | | C. |
proportional to k | | D. |
proportional to the square of k |
Answer: Option B
Explanation:
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| 5. |
The turn on time of an SCR is 5 micro second. Its trigger pulse should have |
| A. |
short rise time with pulse width = 2.5 μs | | B. |
long rise time with pulse width = 3 μs | | C. |
short rise time with pulse width = 4 μs | | D. |
long rise time with pulse width = 4 μs |
Answer: Option C
Explanation:
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