Alternating Currents (27)

Question 1

What is meant by the r.m.s value of an alternating voltage?

Answer 1

The value of constant voltage that produces the same power output as the alternating voltage

same for alternating currents

Question 2

What is the mean power in a resisitive load?

Answer 2

Half the maximum power for a sinusoidal alternating current

Question 3

What is the equation for r.m.s. values for a sinusoidal alternating current/voltage?

Answer 3

Ir = I/√2

Same for Vr, where Vr and Ir are the r.m.s. voltage/current

Question 4

What are single diodes used for in alternating currents?

Answer 4

Half-wave rectification

Question 5

What are four diodes (bridge rectifiers) used for in alternating currents?

Answer 5

• Full wave rectification
• Allows all current to be direct