Electrical Engineering - RL Circuits - Discussion

If pf is 1 means unity than their is less current flow in the circuit i.e. less energy consumed.

loss in RL crt= v^2/(R^2+wL^2)*R.

Loss=v^2/(R^2+wL^2)^1/2*cosθ.
=> loss proportional to pf.

So, the less value of pf is recommended.

P = VI*pf.

Power is directly proportional to power factor. Therefore for minimum power loss pf should be minimum.

Answer D is correct.

If the power factor is very less it means there is a large value of inductance in the circuit. It causes an increase in reactance and a decrease in current. If current decreases then power loss is also decreased for constant resistance. However, the disadvantage of keeping the power factor low is that active power is decreased. Thus to do useful work active power must be increased and power factor must be enhanced.

D is correct.

PF= R/Z.

Which means greater PF has greater has greater R consequently greater losses.

Answer D is correct.

Because we know that energy loss means here works reactive Power [VI SIN (θ) ], and in sine function, if we increase the value of θ then the value will be increased, which means here we have to choose the minimum value of Power factor.

Power factor = true power/ apparent power.

Therefore power factor inversely proportional to apparent power.

Therefore to minimise apparent power which consists of reactive power that causes more loss, we have to decrease power factor.