Basic Electrical

The mechanical power is developed by a DC motor is maximum when (A) Back emf is equal to twice of applied voltage. (B)   Back emf is equal to half of applied voltage. (C)  Back emf is equal to applied voltage. (D) None of above. Answer :-  For motor, Eb = Vt − IaRa Mechanical power … Read more

The concept of V/f control of inverters driving induction motors results in (A) Constant torque operation (B) Speed reversal (C) Reduced magnetic loss (D) Harmonic elimination Answer  So, if we maintain the flux is a constant value, then torque also will be a constant value. Correct Answer is (A) Constant Torque Operation.

Eddy current loss will depends on (A). Frequency(B). Flux density(C). Thickness(D). All of the above Answer is  So eddy current loss will depend upon frequency, flux density and the area of the eddy current loop. Correct answer is (D) All of the above.

ELECTRICAL MCQ A Shunt generator running at 1000 rpm has generated emf of 100 V. If the speed increases to 1200 rpm, the generated emf will be nearly 120 V 140 V 175 V 240 V Answer From When other thing remains constant. E2 = 120 V Correct Answer is 120V.

The unit of resistivity is Ω. Ω – metre. Ω / metre. Ω / m². Answer is The unit of resistivity is Ω – metre.

Series Circuit Figure (A) series circuit. The same current flows through all the resistors. An electric circuit can be arranged in several ways, as long as the path for the electric current is closed. The simplest arrangement is the so-called series circuit. The series circuit has all the elements of the circuit connected onto each … Read more

Function of Wattmeter We have to measure electric power to know how much power any device or apparatus is drawing from the line. A wattmeter registers watts or kilowatts, and by reading it one can tell how much power any piece of apparatus is consuming. The amount of electric power delivered by a circuit depends on … Read more