| 1. | A structure obtained by lightly doped n drift region between the layers of a per junction a PIN diode is obtained. This structure is effective in ? | |
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making the diode support large reverse blocking voltages
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reduction in the voltage spike during turn off due to stray inductance
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making reverse recovery process slow
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making the diode have high on-state voltage drop
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Report Question| 2. | Consider the following statements about a Tunnel diode: 1. Tunnelling takes place at a speed decided by junction temperature. 2. Concentration of impurities is of the order of 1 part in 10. 3. Both tunnelling current and normal pe junction injection current exist 4. Tunnel diode exhibits current controlled negative resistance characteristic only. Which of the above statements is/are correct ? | |
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1 only
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3 and 4
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1 and 2
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2 and 3
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| 3. | Consider the following statements about p- junctions: 1. p-n junction behaves as a capacitor when forward biased. 2 p-n junction has p and n type semiconductors with depletion layer in between 3. p- junction has a wider depletion layer as compared to a zener diode. Which of the statements given above are correct ? | |
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1 and 3 only
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1,2 and 3
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2 and 3 only
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1 and 2 only
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| 4. | Intermediate (I) layer of PIN-diode imparts which one of the following features to a pn junction diode ? | |
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Poor turn off performance
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High forward current rating
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High reverse blocking capability
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Inverting capability
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| 5. | For a Schottky-barrier diode which one of the following points is true ? | |
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There is no P-N junction
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Current is by means of minority carriers
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Speed of operations is low
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I-V characteristics is exactly same as P-N diode
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| 6. | Write the incorrect statement. A varactor diode ? | |
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is often used in an automatic frequency control device
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has variable capacitance
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has always a uniform doping profile
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utilizes transition capacitance of a junction
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| 7. | The emitter of a transistor is generally doped the heaviest because it ? | |
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has to supply the charge carriers
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has to dissipate maximum power
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must possess low resistance
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is the first region of the transistor
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| 8. | In a junction transistor, recombination of electrons and holes occurs in ? | |
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collector region only
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base region only
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emitter region only
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all the 3 regions
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| 9. | A transistor works in three regions: 1. Cut-off 2 Active 3. Saturation. Which is used as switch in digital logic gates, the regions it works in are ? | |
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1,2 and 3
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1 and 2 only
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2 and 3 only
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1 and 3 only
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| 10. | The common-emitter short-circuit current gain beta of a transistor ? | |
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is not a function of lc
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is a monotonically decreasing function of le
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increases with lc for low lc, reaches a maximum and then decreases with further increase in lc
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is a monotonically increasing function of the collector current
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