Electrical Engineering Answers

3. Explain why single phase Induction motor is NOT self-starting?

2. Does transformers work on DC? Justify your answer.

1. A 50 KVA transformer has 400 turns on the primary and 50 turns on the secondary winding. The primary is connected to 2000 V, 50 Hz supply. Find
1) the full load primary and secondary currents
2) the secondary emf.
3) maximum flux in the core

2 mWb is to be produced in the air gap of the magnetic circuit shown in figure 21.17. How much ampere turns the coil must provide to achieve this? Relative permeability μr of the core material may be assumed to be constant and equal to 5000. All the dimensions shown are in cm and the sectional area is 25cm2 through out.

A discrete-time system is described by the following rule
y(n)=(-1)^n x(n) + 2x(n -1)
where x is the input signal, and y the output signal.

Classify the system as:
1-Determined
2-With memory

With an uncontrolled 1-phase half-wave rectifier with a phase voltage of 120 V.
A 10 Ω load is fed. Neglecting circuit losses,
a) Find the output voltage and current.
b) Find the effective phase current.

Why is zener diode used in drivers?

An RLC series circuit has R = 100 ohms, C = 25 µF, and L = 0.16 H. For what angular
frequency of an ac voltage is the current flow maximum?

If an R = 1-kΩ resistor, a C = 1-µF capacitor, and an L = 0.2-H inductor are connected in
series with a V = 150 sin (377t) volts source, what is the maximum current delivered by the source?

When a series RLC circuit is subject to 48 V, VR is 15 V, and VL is 22 V. What is the voltage
across the capacitor?