ACES EE Three Phase Circuit

In a balanced 3- phase Y connected circuit the line voltages are equal

• to the phase voltage

• to 1.414 times the phase voltage

• and so are the line currents

• three times the phase voltage

In the two wattmeter method of measuring power taken by a balanced 3 phase load, if the load power factor is .50, one of the wattmeters will read

• one half of total power

• 0.866 of total power

• 0.707 of total power

• zero

In a 3-phase, 3-wire system, the sum of the line currents are equal to

• 3 x phase current

• sq.rt of 3 x phase current

• the current in the neutral conductor

• zero

Which of the following is not a method in measuring power taken by a balanced 3-phase load using only one wattmeter?

• potential lead shirt method

• Artificial neutral method

• T-method

• Potential transformer method

Using an artificial neutral method, if the wattmeter reads 600 watts, then the total power taken is equal to ___ watts

• 600

• 1200

• 1800

• 900

The T-method is used in measuring the total power taken by a balanced 3-phase load. If the total power is 1200 watts. The wattmeter deflection is watts.

• 1200

• 400

• 800

• 600

What is the minimum number of wattmeters required for measuring power of a balanced 3-phase load?

• one

• two

• three

• four

What is the minimum number of wattmeters required in measuring power in a unbalanced 3-phase load?

• one

• two

• three

• four

In the two watt-meter method with the load balance the reading of the ___ wattmeters will be identical if the power factor is

• 0.50

• 0.707

• unity

• 0.866

In a delta connection of balanced 3-phase load the line current is

• sq.rt of 2 x phase current

• vector sum of the phase currents

• equal to the line current

• sq.rt of 3 x phase currents