$28-$a chopper is a

a$)$ Time ratio controller

c$)$ DC transformer

b$)$ AC to DC convertar

d$)$ High speed semiconductor switch

$29.$ The load voltage of a chopper can be controlled by vary ing die

a$)$ duty cycle

b$)$ firing angle

c$)$ reactor position

d$)$ extinction angle

$30.$ For it step$-$up chopper, when the duty eycle is increased the average value of the output voltage

a$)$ increases

b$)$ decreases

c$)$ remains the same

d$)$ none of the mentioned

$31-$ In a type C chopper, if only one switch is

a$)$ only one quadrant operation will be obtained

b$)$ two quadrant operation can be obtained

c$)$ the chopper won't work

d$)$ none of the mentioned

$32$ What is the voltage across the R load when only T $1$ is conducting?

$a$

roVs

d$)$zero

$33-$A single$-$phase half bridge inverter is connected to a $230$ V de source which is feeding load of $10.$ Determine the fundamental power delivered to the load.

a$)1\mathrm{.}07$ W

b$)107\mathrm{.}2$ W

c$)1\mathrm{.}07$ kW

d$)107\mathrm{.}2$ kW

$34-$ The distortion factor $()$ is the ratio of

a$)$ total rms output voltage to fundamental $rms$ output voltage

b$)$ fundamental rms output voltage to fundamental average output voltage

c$)$ total rms output voltage to rms value of all the harmonic componentsu