Q. Assertion (A): In Hall effect the O.C. transverse voltage developed by a current carrying semiconductor with a steady magnetic field perpendicular to the current direction has opposite signs for n and p semiconductors.

Reason (R): The magnetic field pushes both holes and electrons in the same direction.

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Q. A voltage of 9 V is applied in forward direction to a semiconductor diode in series with a load resistance of 1000 Ω. The voltage across the load resistance is zero. It indicates that

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Q. If the drift velocity of holes under a field gradient of 100 V/m in 5 m/s, their mobility (in SI units) is

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Q. In a bipolar transistor

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Q. If for a silicon n-p-n transistor, the base to emitter voltage (VBE) is 0.7 V and the collector to base voltage VCB is 0.2 Volt, then the transistor is operating in the

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Q. The number of doped regions in a bipolar junction transistor is

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Q. Donor energy level is n type semiconductor is very near valence band.

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Q. GaAs has an energy gap 1.43 eV the optical cut off wavelength of GaAs would lie in the

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Q. The breakdown voltage in a zener diode

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Q. A varactor diode is used for

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Q. One eV = 1.602 x 10¯¹⁹ joules.

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Q. Assertion (A): When VDS is more than rated value the drain current in a JFET is very high.

Reason (R): When VDS is more than rated value, avalanche breakdown occurs.

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Q. If ib is plate current, eb is plate voltage and ec is grid voltage the v-i curve of a vacuum triode is ib = 0.003 (eb + kec)ⁿ. Typical values of k and n are

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Q. Electrons can be emitted from a metal surface due to high electric field.

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Q. In an n type semiconductor the fermi level is 0.35 eV below the conduction band, the concentration of donor atoms is increased to three times. The new position of Fermi level will be

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Q. Assertion (A): In a BJT, the base region is very thick.

Reason (R): In p-n-p transistor most of holes given off by emitter diffuse through the base.

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Q. Assertion (A): The behaviour of FET is similar to that of a pentode.

Reason (R): FETs and vacuum triode are voltage controlled devices.

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Q. SCR can be turned on by

1. applying anode voltage at a sufficient fast rate
2. applying sufficiently large anode voltage
3. increasing the temperature of SCR to a sufficiently
4. applying sufficiently large gate current

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Q. When a diode is not conducting, its bias is

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Q. The SCR would be turned OFF by voltage reversal of applied anode-cathode ac supply of frequency of

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