Q. The skin depth of copper is found to be 66 mm at 1 MHz at a certain temperature. At the same temperature and at 2 MHz, the skin depth would be approximately

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Q. When p-n junction is reverse biased the holes in p material move towards the junction and electrons in n material move away from the junction.

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Q. In which material do conduction and valence bands overlap

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Q. For a photoconductor with equal electron and hole mobilities and perfect ohmic contacts at the ends, an increase in illumination results in

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Q. The number of p-n junctions in a semiconductor diode are

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Q. Assertion (A): A high junction temperature may destroy a diode.

Reason (R): As temperature increases the reverse saturation current increases.

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Q. A Si sample is doped with a fixed number of group N impurities. The electron density n is measured from 4 K to 1200 k for the sample. Which one of the following is correct?

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Q. Assertion (A): In design of circuit using BJT, a derating factor is used.

Reason (R): As the ambient temperature increases, heat dissipation becomes slower.

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Q. If the drift velocity of holes under a field gradient of 100 V/m is 5m/sec. Their mobility is

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Q. In a P type silicon sample, the hole concentration is 2.25 x 10¹⁵ / cm³. If the intrinsic carrier concentration is 1.5 x 10¹ᴼ/ cm³ the electron concentration is

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Q. The behaviour of a JFET is similar to that of

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Q. Dielectric strength of polythene is around

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Q. Resistivity of hard drawn copper is

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Q. The channel of JFET consists of

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Q. In a bipolar junction transistor αdc = 0.98, ICO= 2 μA and 1B = 15 μA. The collector current IC is

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Q. The voltage across the secondary of the transformer in a half wave rectifier with a shunt capacitor filter is 50 volts. The maximum voltage that will occur on the reverse biased diode will be

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Q. As temperature increases the forbidden gap in silicon increases.

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Q. Assertion (A): Germanium is more commonly used than silicon.

Reason (R): Forbidden gap in germanium is less than that in silicon.

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Q. Which of the following devices has substrate?

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Q. Assertion (A): The amount of photoelectric emission depends on the intensity of incident light.

Reason (R): Photo electric emission can occur only if frequency of incident light is less than threshold frequency.

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