• Attempt any five questions.
• All questions carry equal marks.
State and explain Kirchhoff's current and voltage law.
For the circuit shown in Fig (i) find the current in 2Ω resistor.
State and explain Superposition theorem.
Find the current through 5-ohm resistance in Fig (ii) using mesh current analysis.
Define the following with respect to alternating quantity:
i) R.M.S. value,
ii) Peak value,
iii) Average value,
iv) Instantaneous value.
A 4 ohm resistor is connected to a 10 mH inductor across a 100 V, 50 Hz voltage source. Find the input current, voltage across resistor and inductor, power factor of the circuit and the real power consumed to the circuit.
Explain Faraday's laws of electromagnetic induction.
Explain the role of resistance, capacitance and inductance in an electric circuit.
Explain the working principle of a single-phase transformer.
In a 25 kVA, 2000/200 power transformer the iron and copper losses are 350W and 400W respectively. Calculate the efficiency at full load.
Explain with schematic diagram different parts of D.C. machines.
Explain the principle of three phase induction motor.
Draw and explain the V-I characteristic of diode.
Explain the working principle of common base transistor.
Write short notes on any two:
i) Logic gates
ii) R-S flip flop
iii) Compare electric and magnetic circuit
iv) B-H curve
