In PWM method of controlling the average voltage in a DC-DC chopper may be varied by:
a) ON time (Ton) of the switch is varied but the total time period is constant
b) ON time of the switch (Ton) is kept constant and OFF time of the switch (Toff) is variable
c) OFF time of the switch (Toff) is kept constant and ON time of the switch (Ton) is variable
From the above the correct statements are:
1
a) and b) only
2
a) only
3
b) and c) only
4
a) and c) only