Define and explain the following terms:

Resistivity

Conductivity

Potential Difference

Resistance Temperature Coefficient

For the given circuit shown in Figure calculate if power dissipated in the circuit is 70 W when applied voltage is 20 V across the circuit.

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By using Superposition Theorem, find the current in R 1 ohm resistor for the circuit shown in Figure 2.

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State and prove Thevenin's Theorem.

Distinguish between primary and secondary cells.

Explain the constant current method of charging battery.

Derive the expression for the force experienced by a current carrying conductor placed in a magnetic field.

What do you understand by magnetic circuit? Explain the terms reluctance and magnetomotive force of a magnetic circuit.

What do you understand by statically and dynamically induced emf? Write down the difference between them with examples.

Prove that the energy stored in an inductor is 1/2 LI^2

An alternating current is represented by i =70·7 sin 520t. Determine the frequency, rms and average value of the current.

Define the following:

Active Power

Reactive Power

Apparent Power

Power Factor

Explain resonance in parallel circuits.

An R-L series circuit as shown in Figure 3 is connected across 240 50 Hz, 1-phase a.c. supply. If the voltage drop R is 100 then find the voltage drop across the inductor L and also the value of L.

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Derive the relation between line current and phase current for a three-phase three-wire system.

What are the advantages of a three-phase system over a single phase system?