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

Which one of the following helps experimental confirmation of the Crystalline state of matter?

The electrical conductivity of pure semiconductor is:

Consider the following statements pertaining to the resistance of a conductor:
1. Resistance can be simply defined as the ratio of voltage across the conductor to the current through the conductor. This is, in fact, Georg Ohm’s law.
2. Resistance is a function of voltage and current.
3. Resistance is a function of conductor geometry and its conductivity
Which of the above statements are correct?

The ratio of ionic radii of Cations i.e.and that of Anions i.e.for stable and unstable ceramic crystal structure, is:

Which one of the following statements is correct?

In an extrinsic semiconductor the conductivity significantly depends upon:

In some substances when an electric field is applied the substance become polarized. The electrons and nucleii assume new geometrical positions and the mechanical dimensions are altered. This phenomenon is called:

In ferromagnetic materials, the net magnetic moment created due to magnetization by an applied field as:

At what temperatures domains lose their ferromagnetic properties?

Which of the following materials does not have paramagnetic properties?
1. Rare earth elements (with incomplete shell)
2. Transition elements
3. Magnesium oxide
Select the correct answer from the codes given below:

In a superconducting magnet, wires of superconducting material are embedded in the thick copper matrix, because while the material is in the superconducting state:

The crystal structure of some Ceramic materials may be thought of being composed of electrically charged Cations and Anions, instead of Atoms, and as such:

Manganin alloy used for making resistors for laboratory instruments contains:

A rolled-paper capacitor of value 0.02  is to be constructed using two strips of aluminiumof width 6 cm, and wax impregnated paper of thickness 0.06 mm whose relative permittivity is 3. The length of foil strips should be:

In a semiconductor diode, cut-in voltage is the voltage:

Which of the following regions of operation are mainly responsible for heating of the transistor under switching operation?
1. Saturation region
2. Cut-off region
3. Transition from saturation to cut-off
4. Transition from cut-off to saturation
Select the correct answer using the codes given below

In a sinusoidal oscillator, sustained oscillations will be produced only if the loop gain (at the oscillation frequency) is

The Class-B push-pull amplifier is an efficient two –transistor circuit, in which the two transistors operate in the following way:

PAC stands for______.

For normal operation of a transistor

Consider the following statements regarding linear power supply:
1. It requires low frequency transformer.
2. It requires high frequency transformer.
3. The transistor works in active region.
Which of the above statements is/are correct?

A full wave rectifier connected to the output terminals of the mains transformer produces an RMS voltage of 18 V across the secondary. The no-load voltage across the secondary of the transformer is

MICR stands for______.

In an Op-Amp, if the feedback voltage is reduced by connecting a voltage divider at the output, which of the following will happen?
1. Input impedance increases
2. Output impedance increases
3. Overall gain increases
Which of the above statements is/are correct?

The transient response rise time (unity gain) of an Op-Amp is 0.05s.The small signal bandwidth is

A negative feedback of   is applied to an amplifier of open-loop gain 1000. What is the change in overall gain of the feedback amplifier, if the gain of the internal amplifier is reduced by 20%?

If the quality factor of a single-stage single tuned amplifier is doubled, the bandwidth will

Consider the following statements related to oscillator circuits:
1. The tank circuit of a Hartley oscillator is make up of a tapped capacitor and a common inductor.
2. The tank circuit of a Colpitts oscillator is make up of a tapped capacitor and a common oscillator.
3. The Wien Bridge oscillator is essentially a two-stage amplifier with an RC bridge in the first stage, and, the second stage serving as inverter.
4. Crystal oscillators are fixed frequency oscillators with a high Q-factor.
Which of the above statements are correct?

The most commonly used transistor configuration for use as a switching devices is

The simplified form of the Boolean expression AB + A (B + C) + B(B + C) is given by

Consider the following statements:
The output of a linear circuit, driven with a sine wave at a frequency f, is itself a sine wave
1. at the same frequency
2. with chance of changed amplitude
3. with chances of changed amplitude and phase
Which of the above statements is/are correct? 

Consider the following statements:
The main contribution to photo conduction is by
1. the generation of electron and hole pair by a photon
2. a donor electron jumping into the conduction band because of a photon’s energy
3. a valence electron jumping into an acceptor state because of a photon’s energy Which of the above statements is/are correct? 

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

For the same network, with 6 V DC connected at port A, 1 Ω connected at port B draws 7/3 A. if 8 V DC is connected to port A, the open circuit voltage at port B is

A signal may have frequency components which lie in the range of 0.001 Hz to 10 Hz. Which one of the following types of couplings should be chosen in a multistage amplifier designed to amplify the signal? 

If an input impedance of op-amp is finite, then which one of the following statements related to virtual ground is correct ? 

Hysteresis is desirable in a Schmitt-trigger because 

In a photoconductive cell the resistance, of the semiconductor material varies with intensity of incident light. 

In graded index multimode optical fiber the refractive index of the core is

Consider the following factors:
1. Number of turns of the coil
2. Length of the coil
3. Area of cross-section of the coil
4. Permeability of the core
On which of the above factors does inductance, depend?