JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech I Year BASIC ELECTRICAL AND ELECTRONICS ENGINEERING Previous Question Paper (May - 2018 - R16)

Define dependent sources.

The essential component of a toaster is an electrical element (a resistor) that converts electrical energy to heat energy. How much current is drawn by a toaster with resistance 15Ω at 110 V?

What is the condition for maximum power transfer in ac circuits?

Derive the expression for resonant frequency.

Define reverse break down voltage of a diode.

Derive an expression for the average output voltage of a full wave rectifier.

Draw the high frequency model of a transistor.

In a BJT, the emitter current is 12 mA and the emitter current is 1.02 times the collector current. Find the base current.

Why FET is called unipolar device?

What are the special features of FET?

Differentiate between active and passive elements.

Obtain the equivalent resistance for the circuit in figure 1 and use it to find current i.

Define impedance, susceptance and admittance with examples.

Using mesh analysis, find Io in the circuit shown in figure 2.

The Q factor of a RLC series circuit is 5 at a resonance frequency of 1 KHz. Assuming the power dissipation of 250W, when the current drawn is 1A, find the circuit parameters.

Using superposition, find Vo in the circuit shown in figure 3.

A 5 µF condenser is connected in series with a coil having inductance of 50mH. Determine the frequency of resonance, the resistance of the coil if a 50V source causing a current of 10mA is connected. What is the Q factor of the coil?

Use Norton’s theorem to find Vo in the circuit shown in figure 4.

Draw the V – I characteristics of a silicon diode, write an expression for diode current and discuss how cut in voltage changes with temperature.

Draw the circuits of a full wave rectifier using 2-diodes and 4-diodes. Discuss the relative merits and demerits.

Define diffusion capacitance in a P-N junction diode and discuss its dependence on diode biasing.

Derive expressions for ripple factor and efficiency of rectification for a full wave rectifier.

Derive expressions for voltage gain, input-resistance and current gain for an emitter follower.

In the Silicon Transistor circuit shown in figure 5, find the maximum base resistance RB to drive the Transistor into saturation.

Discuss the need for biasing a transistor. Briefly explain about self biasing.

Explain how h-parameters can be determined from the static input and output characteristics.

Discuss the characteristic differences between a BJT and a FET. Draw a diagram depicting the structure of a N-channel FET and identify the various terminals and the biasing voltages.

Explain how the pinch off voltage can be modified without changing the physical structure of a JFET.

Explain the operation of a FET with a neat diagram and V-I characteristics.

An N-channel JFET has a pinch voltage of -4.5V and IDSS = 9mA at what value of VGS will IDS equal to 3mA? What is its gm at this IDS.