Electrician sem1 mod6 AC circuits

What is the unit of susceptance?

• Mho

• Ohm

• Henry

• Farad

What is the resistance of the inductive coil takes 5A current across 240V, 50Hz supply at 0.8 power factor?

• 48 Ω

• 42.5 Ω

• 38.4 Ω

• 26.6 Ω

How the resonance frequency (fr) can be increased in A.C series circuit?

• Increasing the inductance value

• Reducing the capacitance value

• Increasing the capacitance value

• Increasing the value of resistance

What is the main cause for below 0.5 lagging power factor in 3 phase system?

• Due to fluctuation of voltage

• True power due to resistive load

• Reactive power due to more inductive load

• Reactive power due to more capacitive load

What is the current in neutral conductor in 3 phase unbalanced load in star connected system?

• No current will flow

• The algebraic sum of current in 3 phases

• The algebraic sum of current in 2 phases only

• Lesser than the lowest current in any one of the phases

Calculate the apparent power in KVA of 3 phase 415V, 50 Hz, star system, if the line current (IL) is 16A at 0.8 power factor.

• 15.2 KVA

• 11.5 KVA

• 9.2 KVA

• 5.3 KVA

What will be the readings of two watt meters (W1& W2) in 3 phase power measurement, if the power factor is zero?

• W1 & W2 both are positive reading

• W1 is Positive and W2 is negative reading

• W1 is equal to W2 but with opposite signs

• Zero W1 is Positive reading, and W2 is negative reading

What is the maximum value of voltage for 240 volt RMS?

• 240V

• 415V

• 339.5V

• 376.8V

What is the formula for Reactive Power (Pr) in an AC circuit?

• Pr = VI

• Pr = √2 VI

• Pr = VI cos θ

• Pr = VI sin θ