Engineers day quiz

What happens to the MMF when the magnetic flux decreases?

• Increases

• Decreases

• Remains constant

• Becomes zero

The power factor of a D.C. circuit is always

• Less than unity

• Unity

• Greater than unity

• zero

Which one is the correct unit of the reactive power ?

• kW

• kVAr

• VA

• kVA

True power is defined as

• VI Cos Φ

• VI

• VI Sinθ

• None of these

What is the power factor in a pure resistive circuit?

• 0

• -1

• 1

• Infinity

What is the power factor in a pure inductive or capacitive circuit?

• -1

• 1

• Infinity

• 0

if P= cosΦ ,find P for power triangle for series RL circuit using diagram.

• Q/P

• P/S

• S/P

• S/Q

Equation for Apparent power is ________

• VI sin θ

• VI cos θ

• VI

• None of the above

when the phase difference of circuit is 90 degree and current leads the voltage, this circuit is known as

• Series RC circuit

• series RL circuit

• Pure capacitance circuit

• Pure inductive circuit

 

find the Φ using diagram for impedance triangle.

• Φ= tan^-1[XL/Z]

• Φ= tan^-1[R/Z]

• Φ= tan^-1[z/XL]

• Φ= tan^-1[XL/R]