111. Which of the following doping will produce P type semi-conductor
a. Germanium and Antimony
b. Germanium with Phosphorous
c. germanium with Indium
d. Silicon with Indium

112. The difference between a hole and electron is that a hole
a. always remain in the valence band
b. has no momentum
c. has no mass
d. has no inertia

113. When an electron rises through a potential of 100V, it will acquire an energy of
a. 100 eV
b. 100 joules
c. 100 ergs
d. 100 exponent -6 Newtons

114. Hali,s effect can be used to measure
a. magnetic field intensity
b. average number of holes
c. carriers concentration
d. electrostatic field intensity

115. Which photo conductor is commonly used?
a. Pbs
b. Cds
c. GaAs
d. AsBr

116. The photo electric treshold of tungsten is 2300 A . The energy of the electrons ejected from the surface by ultra-violet light of wave length 1800 A , will be
a. 0.15 eV
b. 1.5 eV
c. 150 eV
d. 1.5 keV

117. A solar cell is an example of
a. Photo voltaic cell
b. Photo conductive cell
c. Photo emissive cell
d. Photo radiation cell

118. Barrier potential for silicon diode
a. 0.3 V
b. 0.4 V
c. 0.1 V
d. 0.7 V

119. When light is directed at the metal surface , the emitted electrons
a. are called photons
b. have random energies
c. have energies that depend upon intensity of light
d. have energies that depend upon frequency of light

120. A strong electric field across a P-N junction that cause covalent bonds to break part
a. it is called balance breakdown
b. it is called reverse break down
c. is is called lever breakdown
d. it is called low voltage breakdown