POWER ELECTRONICS AND DRIVES PART 22

POWER ELECTRONICS AND DRIVES PART 22

1. In the figure shown below, the capacitor C is used to

a) maintain the load voltage constant
b) protect the load
c) protect the chopper switch (SW)
d) maintain the load current constant
Answer:a

2. In the below shown step-up/step-down chopper circuit, when the switch (SW) is on
 
a) current through inductor rises and the load voltage is zero
b) current through inductor rises and the load voltage is Vs
c) current through inductor decays and the load voltage is zero
d) current through inductor decays and the load voltage is Vs
 

Answer: b

3. For a step-up/step-down chopper, if α (duty cycle) < 0.5 then
a) Vo = Vs
b) Vo < Vs
c) Vo > Vs
d) none of the mentioned
 

Answer: b

4. In the below shown step-up/step-down chopper circuit, when the chopper switch (SW) if first on and then off, then the current flows from path

a) Vs-CH-L-Vs
b) L-Load-D-L
c) L-D-Load-L
d) no current flows
 

Answer: b

5. For a step-up/step-down chopper, if current increases from I1 to I2 linearly during Ton, then find the energy stored in the inductor during Ton
a) zero
b) Vs x (I1 + I2)
c) Vs x [ (I1 + I2)/2 ] x Ton
d) Vs x [ (I1 + I2)/2 ] x T
 

Answer: c

6. A step-down chopper is also called as a
a) first-quadrant chopper
b) second-quadrant chopper
c) third-quadrant chopper
d) fourth-quadrant chopper
 

Answer: a

7. For the type-B chopper shown below
 
a) during Ton, Vo = 0 and L stores energy
b) during Ton, Vo is not 0 and L stores energy
c) during Ton, Vo = 0 and L releases energy
d) during Ton, Vo is not 0 and L releases energy
 

Answer: a

8. For the type-B chopper shown below
 
a) during Toff, Vo = (E + Ldi/dt) and D is conducting
b) during Toff, Vo = (E + Ldi/dt) and D is not-conducting
c) during Toff, Vo = 0
d) during Toff, Vo = Vs
 

Answer: a

9. The below given chopper is that of a

a) step-up chopper
b) step-down chopper
c) step-up/step-down chopper
d) depends on the duty cycle
 

Answer: a

10. The type-C chopper or two quadrant type-A chopper has
a) type-A and type-B choppers in series
b) type-A and type-B choppers in parallel
c) two type-A choppers in series
d) two type-A choppers in parallel
 

Answer: b