Q.1
The below given circuit can
Questionpower-electronics-questions-answers1.jpg
  • a) operate in all the four quadrants
  • b) operate in only the first and second quadrant
  • c) operate in only the fourth and third quadrant
  • d) operate in only the first and fourth quadrant
Q.2
In the below shown chopper circuit, when CH3 is on
Questionpower-electronics-questions-answers2.jpg
  • a) both load voltage and current are zero
  • b) both load voltage and current are positive
  • c) both load voltage and current are negative
  • d) none of the mentioned
Q.3
In the below given type E chopper circuit, when CH3 and CH2 are switched on and then CH3 is switched off after some time, then
Questionpower-electronics-questions-answers3.jpg
  • a) load current falls to zero
  • b) negative current freewheels through CH2, D4
  • c) positive current freewheels through CH2, D4
  • d) none of the mentioned
Q.4
For the type E chopper to be operated in the fourth quadrant
  • a) only one switch is operated
  • b) two switches are operated
  • c) three switches are operated
  • d) all the switches are operated
Q.5
For the fourth quadrant operation, the current flows through
Questionpower-electronics-questions-answers5.jpg
  • a) CH1, D2, L and D1
  • b) CH4, D3, L and D4
  • c) CH4, D2, L and E
  • d) CH1, D2, L and D3
Q.6
When CH4 is turned on and then off
Questionpower-electronics-questions-answers6.jpg
  • a) load current falls to zero
  • b) negative current freewheels through D2, D3
  • c) positive current freewheels through D2, D3
  • d) none of the mentioned
Q.7
Find the expression for the ripple factor in terms of duty cycle α for a type A step down chopper
  • a) √(1-α/α)
  • b) α2/2
  • c) √α/2
  • d) √(1-α)
Q.8
The AC ripple voltage is given by
  • a) Vrms/Vo
  • b) Vrms2/π
  • c) √(Vrms2 – Vo2)
  • d) √(Vrms + Vo)
Q.9
The expression for the thyristor (chopper switch) current is given by
  • a) 2Vs/π
  • b) 180°
  • c) E/2Vs
  • d) Vs/R
Q.10
In a type E chopper, if all the four chopper switches are closed simultaneously then
  • a) load is short circuited
  • b) supply is short circuited
  • c) both load and supply are shorted
  • d) none of the mentioned.
Q.11
A type A step down chopper has Vs =V and is connected to RLE load. With R = 1 Ω, E =V and L large enough to maintain continuous conduction. Find the average value of load current for a duty cycle of%.
  • a) 100 A
  • b) 22 A
  • c) 42 A
  • d) 16.5 A
Q.12
A step down chopper has Vs =V and is connected to RLE load. With R = 1 Ω, E =V and L = 5 mH. The chopping period isμs and the on-period isμs. Find the value of minimum steady state output current.
  • a) 33 A
  • b) 42 A
  • c) 0 A
  • d) 51 A
0 h : 0 m : 1 s