At temperature of 298 Kelvin, Silicon is not suitable for most-electronic applications, due to small amount of conductivity. This can be altered by

By doping Germanium with Gallium, the types of semi-conductors formed are
1. N type
2. P type
3. Intrinsic
4. Extrinsic

An n-type of silicon can be formed by adding impurity of:
1. Phosphorous
2. Arsenic
3. Boron
4. Aluminum 
Which of the above are correct ?

According to Einstein’s relationship for a semiconductor, the ratio of diffusion constant to the mobility of the charge carriers is

Swept-out voltage in PIN diode happens when PIN diode is

The number of holes in an N-type silicon with intrinsic value 1.5 × 10¹⁰/cm³ and doping concentration of 10¹⁷/cm³, by using mass-action law is

A tunnel-diode is best suited for

Small recovery time of a diode is most significant for

In JFET, when operated above the pinch-off voltage, the

Thermal runaway is not possible in FET because, as the temperature of FET increases

Consider the following statements regarding an N-P-N Bipolar Junction Transistor:
1. Emitter diode is forward biased and collector diode is reverse biased
2. Emitter has many free electrons
3. Free electrons are injected into base and pass through collector
4. Depletion layers around junction J1 and J2 of BJT are widened 
    Which of the above statements are correct?

A freewheeling diode T phase controlled rectifier

The zeners incorporated within the encapsulations of some MOSFETs are meant for

When UJT is used for triggering an SCR, the wave-shape of the signal obtained from UJT circuit is

Darlington pairs are frequently used in linear ICs because, they

In a MOS capacitance fabricate on a P-type semiconductor, strong inversion occurs, when potential is

A CMOS amplifier when compared to an N channel MOSFET has the advantage of

Consider the following statements regardingoptocouplers:
1. Optocouplers are LEDs driving photodiodes in a single package to provide electrical isolation between input and output
2. Optocouplers is LED driving a phototransistor in a single package that replaces pulse transformers working at input zero crossing
3. Optocouplers are used as temporary non fixed joints between optical fibre terminations 
  Which of the above statements are correct?

Which of the following does not cause permanent damage to an SCR ?

The basic structure of an avalanche photodiode is

A five digits number is formed using the digits 1, 3, 5, 7 and 9 without repeating any of them. What is the sum of all such possible five digit numbers ?

Examples of an active display and a passive display respectively are

The dc resistivity and permeability exhibited by a type 1 superconductor are respectively

Statement (I):One of the mechanisms by which a transistor’s usefulness may be terminated, as the collector voltage is increased, is called punch through.
Statement (II): Punch through results from the increased width of the collector-junction transition region with increased collector-junction voltage

Statement (I): Conduction takes place in an enhancement MOSFET only for gate voltages below the threshold level.
Statement (II):In an enhancement MOSFET, a channel of semiconductor of the same type as the source and drain is induced in the substrate by a positive voltage applied to the gate.

Resistance switching is normally resorted in case of

By transmitting power at high voltage

Which statement about the daily load curve is valid ?

High voltage Schring bridge is used to measure

Draw - in - system of laying underground cables has the drawback (s) of

Surge impedance of a transmission line is

If two synchronous generators connected in parallel loose synchronism, it will lead to

A differential relay responds to

The conductor carries more current on the surface in comparison to its core. This phenomenon is called the

A booster is connected in

Fuses have got advantages of

The power transmitted will be maximum when

The connected load of a consumer is 2 kW and his maximum demand is 1.5 kW. The load factor of the consumer is

In a transformer, the exciting current will be in phase quadrature with the impressed voltage provided

Which of the following techniques is used for the measurements of a.c. high frequency voltages ?

Use of additional shunt capacitor can be made for increasing the capability of line as it

The sag of a transmission line is least affected owing to

In case of Impulse Thermal break down of solid insulating materials, the critical electric field is proportional to

The insulation of the modern EHV lines is designed based on

For constant voltage transmission, the voltage drop along the line is maintained constant by installing

AC network analyser is employed for solving the problems of

The change in excitation in an alternator connected to an infinite line provides a corresponding change in

Different types of insulators used for transmission lines are

The conductor connecting consumer's terminals to the distributor is called the

Which of the following method or techniques can be used for the measurement of high d.c. voltages ?