Multiple Choice QuestionsWhich one of the following statement is false?
Pure Si doped with trivalent impurities given a p- type semiconductor
Majority carriers in a p- type semiconductor are holes
Minority carriers in a p- type semiconductor are electron
Minority carriers in a p- type semiconductor are electron
A.
Pure Si doped with trivalent impurities given a p- type semiconductor
p-type semiconductor is obtained by adding a small amount of trivalent impurity to a pure sample of semiconductor (Ge).
Majority charge carriers - holes
Minority charge carriers - electrons
n - type semiconductor are obtained by adding a small amount of pentavalent impurity to a pure sample of semiconductor (Ge)
Majority charge carriers - electrons
The resistance of intrinsic semiconductors decreases with the increase of temperature.
A ray of light travelling in a transparent medium of refractive index μ falls, on a surface separating the medium from the air at an angle of incidence of 45o. For which of the following value of μ the ray can undergo total internal reflection?
μ =1.33
μ = 1.40
μ = 1.50
μ = 1.50
The activity of a radioactive sample is measured as No counts per minute at t = 0 and No/e counts per minute at t = 5 min. The time (in minute) at which the activity reduces to half its value is
loge 2 /5
5/ loge 2
5 log10 2
5 log10 2
The device that can act as a complete electronic circuit is
Junction diode
Integrated circuit
Junction transistor
Junction transistor
The energy of a hydrogen atom in the ground state is -13.6 eV. The energy of a He+ ion in the first excited state will be
-13.6 eV
-27.2 eV
-54.4eV
-54.4eV
A lens having focal length f and aperture of diameter d forms an image of intensity I. The aperture of diameter d/2 in the central region of the lens is covered by a black paper. Focal length of lens and intensity of image now will be respectively
f and 1/4
3f/4 and 1/2
f and 3I/4
f and 3I/4
A source S1 is producing, 1015 photons of wavelength 500 A. Another source S2 is producing 1.02 x 1015 photons per second of wavelength 5100 A. Then, power of S2) (power of S1) is equal to
1.00
1.02
1.04 A
1.04 A
A common emitter amplifier has a voltage gain of 50, an input impedance of 100 Ω and an output impedance of 200 Ω. The power gain the amplifier is
500
1000
1250
1250
The potential difference that must be applied to stop the fastest photoelectrons emitted by a nickel surface, having work function 5.01 eV, when ultraviolet light of 200 nm falls on it, must be
2.4 V
-1.2 V
-2.4 V
-2.4 V
To get an output Y = 1 from the circuit shown below, the input must be
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