MONTHLY TRADE TEST OF FEB - 2024

What is the maximum voltage value for a standard 240 volt RMS power supply?

• 240V

• 415V

• 339.5V

• 376.8V

What is the power factor if one of the wattmeter gives negative reading in two wattmeter method of 3 phase power measurement?

• 0

• 0.5

• Unity

• Less than 0.5

Which formula is used to calculate the impedance (z) of a RLC series circuit?

• 𝑍=𝑅2+(𝑥𝐿~ xc)2

• 𝑍=√𝑅2+(𝑥𝐿~ xc)

• 𝑍=√𝑅+(𝑥𝐿~ xc)

• 𝑍=√𝑅2+(𝑥𝐿~ xc)2

Which quantity is rotating at a constant angular velocity?

• Scalar quantity

• Vector quantity

• Phasor quantity

• Algebraic quantity

How will you obtain positive reading in the wattmeter reads negative reading during 3- phase two wattmeter method?

• By interchanging the connections of input terminals

• By reversing the connection of pressure coil in meter

• By disconnecting the connection of current coil in meter

• By reversing the pressure coil and current coil connection in meter

In which situation will resonance occur in an R-LC series circuit?

• Inductive reactance (XL) is zero.

• Inductive reactance (XL) is equal to capacitive

  reactance (XC).

• Inductive reactance (XL) is greater than

  capacitive reactance (XC).

• Inductive reactance (XL) is less than capacitive

  reactance (XC).

Calculate the power factor of a household circuit with a resistance (R) of 15W and a resultant reactance (X) of 20W connected across a 240V /50Hz AC supply?

• 0.5

• 0.6

• 0.7

• 0.8

Calculate the value admittance (Y) of the RLC parallel circuit connected across 240volts/50Hz AC supply and 8 Amp. Current is passed through it ?

• 0.33 Mho

• 3.33 Mho

• 0.033 Mho

• 0.003 Mho

What is the phase displacement in a single phase AC circuit?

• 90°

• 120°

• 180°

• 45°

What is the unit of permeance?

• Ampere - turns

• Weber/Ampere turns

• Ampere turns/Weber

• Weber/Square metre