(1). In a p-n junction photo cell, the value of the photo-electromotive force produced by monochromatic light is proportional to

• (a). the voltage applied at the p-n junction
• (b). the barrier voltage at the p-n junction
• (c). the intensity of the light falling on the cell
• (d). the frequency of the light falling on the cell
• (e). None of these

(2). choose the only false statement from the following

• (a). in conductors the valence and conduction bands may overlap
• (b). substances with energy gap of the order of 10 e V are insulators
• (c). the resistivity of a semiconductor increases with increase in temperature
• (d). the conductivity of a semiconductor increases with increase in temperature
• (e). None of these

(3). Which one of the following statement is false?

• (a). pure si doped with trivalent impurities gives a p-type semiconductor
• (b). majority carriers in a n-type semiconductor are holes
• (c). minority carriers in a p-type semiconductor are electrons
• (d). the resistance of intrinsic semiconductor decreases with increase of temperature
• (e). None of these

(4). The device that can act as a complete electronic circuit is

• (a). junction diode
• (b). integrated circuit
• (c). junction transistor
• (d). zener diode
• (e). None of these

(5). A common emitter amplifier has a voltage gain of 50, an input impedance of 100? and an output impedance of 200? the power gain of the amplifier is

• (a). 500
• (b). 1000
• (c). 1250
• (d). 50
• (e). None of these

(6). For transistor action A) base, emitter and collector regions should have similar size and doping concentrations B) the base region must be very thin and lightly doped C) the emitter-base junction is forward biased and base-collector junction is reverse based D) both the emitter-base junction as well as the base-collector junction are forward biased

• (a). C and D
• (b). D and A
• (c). A and 2
• (d). B and C
• (e). None of these

(7). In following biasing of the p-n junction

• (a). the positive terminal of the battery is connected to p-side and the depletion region becomes thick
• (b). the positive terminal of the battery is connected to n-side and the depletion region becomes thin
• (c). the positive terminal of the battery is connected to n-side and the depletion region becomes thick
• (d). the positive terminal of the battery is connected to p-side and the depletion region becomes thin
• (e). None of these

• (a). 1
• (b). 2
• (c). 3
• (d). 4
• (e). None of these

• (a). NAND gate
• (b). NOR gate
• (c). OR gate
• (d). AND gate
• (e). None of these

• (a). 50
• (b). 75
• (c). 100
• (d). 25
• (e). None of these