. The barrier potential of a p-n junction depends on i) type of semiconductor material ii) amount of doping iii) temperature. Which one of the following is correct? (NEET) a) (i) and (ii) only b) (ii) only c) (ii) and (iii) only d) (i) (ii) and (iii) . To obtain sustained oscillation in an oscillator, a) Feedback should be positive b) Feedback factor must be unity c) Phase shift must be or 2π d) All the above .
If the input to the NOT gate is A = , its output is a) b) c) d) . Which one of the following represents forward bias diode? (NEET) I. Multiple choice questions . The barrier potential of a silicon diode is approximately, a) .
V b) .3V c) . V d) .2V . If a small amount of antimony (Sb) is added to germanium crystal, (AIPMT ) a) it becomes a p-type semiconductor b) the antimony becomes an acceptor atom c) there will be more free electrons than hole in the semiconductor d) its resistance is increased . In an unbiased p-n junction, the majority charge carriers (that is, holes) in the p -region diffuse into n -region because of a) the potential difference across the p-n junction b) the higher hole concentration in p -region than that in n-region c) the attraction of free electrons of n -region d) All of the above .
If a positive half –wave rectified voltage is fed to a load resistor, for which part of a cycle there will be current flow through the load? a) – b) – c) – d) – . The zener diode is primarily used as a) Rectifier b) Amplifier c) Oscillator d) Voltage regulator . The principle based on which a solar cell operates is a) Diffusion b) Recombination - - - - - - - - Unit electronics and Communication c) Sky wave propagation d) Satellite communication Answers .