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Worksheets15. Semiconductors
Total questions: 10
Worksheet time: 50mins
A solid, which is having uppermost energy band (conduction band) partially filled, at room temperature, is called
a conductor.
an insulator.
a semiconductor.
a superconductor.
The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than 2480 mm is incident on it. Find the band gap of the semiconductor. Given: h=6.63×10–34 Js and 1eV=1.6×10–19 J. The energy band of the semiconductor is
0.5 eV
1.0 eV
0.25 eV
1.5 eV
At what temperature would an intrinsic semiconductor behave like a perfect insulator?
0 °C
–200 °C
0 K
200 K
When the voltage drop across a p–n function diode is increased from 0.60 V to 0.65 V, the change in the diode current is 5 A. What is the dynamic resistance of the diode?
0.01 Ω
0.02 Ω
0.03 Ω
0.04 Ω
Determine the currents through the resistance R of the circuits (a) and (b) in the following figure when similar diodes D1 and D2 are connected as shown.
0, 0.1 A
0.1 A, 0
0.1 A, 0.1 A
0 A, 0 A
The diode shown in the circuit in the given figure has a constant potential drop of 0.5 V at all currents and a maximum power rating of 100 mW. What should be the value of the resistance R connected in series with the diode for obtaining the maximum current?
2Ω
3Ω
4Ω
5Ω
A p–n photodiode is fabricated from a semiconductor with band gap of 2.8 eV. It detects an approximate wavelength of
10,000 nm
1000 nm
750 nm
400 nm
When a p–n junction diode is reverse biased, then
the electrons and holes are attracted towards each
other and move towards the depletion region.
the width of the depletion layer increases.
the height of the potential barrier decreases.
no change in current takes place.
A p–n junction diode (D), as shown in the figure, can act as a rectifier. An alternating current source (V) is connected in the circuit. The current in the resistor (R) can be shown by
A p–n junction diode is connected to a battery of emf 5.5 V and external resistance 5.1 kΩ. The barrier potential in the diode is 0.4 V . The current in the circuit is
1 A
1 mA
2 mA
0.08 mA
