Q.1 A zener diode works on the principle of
A. Tunnelling of charge carriers across the junction
B. Thermionic emission
C. Diffusion of charge carriers across the junction
D. Hopping of charge carriers across the junction
Q.2 When a thyristor is negatively biased.
A. All the three junctions are negatively biased
B. Outer junctions are positively biased and the inner junction is negatively biased
C. Outer junctions are negatively biased and the inner junctions is positively biased
D. The junctions near the anode is negatively biased and the one near the cathode is positively biased.
Q.3 Static indictions thyristors have
A. High dv/dt and low di/dt
B. Low dv/dt and high di/dt
C. Low dv/dt and low di/dt
D. High dv/dt and high di/dt
Ans : D
Q. 4 A power MOSFET is a
A. Voltage controlled device
B. Current controlled device
C. Frequency controlled device
D. None of the above
Q.5 Which of the following is preferred for VHF/UHF applications.
Q.6 In a conventional reverse blocking thyristor
A. External layers are lightly doped and internal layers are heavily doped
B. External layers are heavily doped and internal layers are lightly doped
C. The p layers are heavily doped and the n layers are lightly doped
D. The p layers are lightly doped and the n layers are heavily doped.
Q.7 MOS controlled thyristors have
1. Low forware voltage drop during conduction
2. Fast turn on and turn of time
3. Low switching losses
4. High reverse voltage blocking capability
5. Low gate input impedance
A. 1, 2 and 3 are correct
B. 3, 4 and 5 are correct
C. 2, 3 and 4 are correct
D. 1, 3 and 5 are correct
Q.8 In a power mosfet switching time are of the order of few.
Thanks for reading.