Q. An n type silicon bar 0.1 cm long and 100 μm² in cross-sectional area has a majority carrier concentration of 5 x 10²ᴼ/m³ and the carrier mobility is 0.13 mᴼ/V-s at 300k. If the charge of an electron is 1.6 x 10¯¹⁹ coulomb, then the resistance of the bar is

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Q. The threshold voltage of a MOSFET can be lowered by

1. using thin gate oxide
2. reducing the substrate concentration
3. increasing the substrate concentration.

Of the above statement

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Q. In which device does the extent of light controls the conduction

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Q. A Varactor diode has

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Q. The most important set of specifications of transformer oil includes

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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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