#### Electrical engineering

• ( 1 ) Which of the following semiconductor materials is (are) used in the manufacturing of tunnel diodes?

• 1) Germanium
• 2) Gallium
• 3) Both germanium and gallium arsenide
• 4) Silicon
• Discussion in forum
Answer : 3) Both germanium and gallium arsenide
Solution : Germanium and Gallium arsenide used in the manufacturing of tunnel diodes.

discussion

Answer : 3) Both germanium and gallium arsenide

• ( 2 ) Which of the following diodes has a negative-resistance region?

• 1) Schottky
• 2) Tunnel
• 3) Varactor
• 4) Power
• Discussion in forum
Solution : Tunnel diodes has a negative-resistance region.

discussion

• ( 3 ) Which among the following does not belong to the category of LC oscillators?

• 1) Hartley oscillator
• 2) Colpitt's oscillator
• 3) Clapp oscillator
• 4) Wein bridge oscillator
• Discussion in forum
Answer : 4) Wein bridge oscillator
Solution : Wein bridge oscillator does not belong to the category of LC oscillators.

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Answer : 4) Wein bridge oscillator

• ( 4 ) Multivibrators belong to the category of _____________

• 1) Square wave oscillators
• 2) Triangular wave oscillators
• 3) Ramp wave oscillators
• 4) Sinusoidal oscillators
• Discussion in forum
Answer : 1) Square wave oscillators
Solution : Multivibrators belong to the category of Square wave oscillators.

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Answer : 1) Square wave oscillators

• ( 5 ) What should be the value of input resistance for an ideal voltage amplifier circuit?

• 1) Unpredictable
• 2) Infinity
• 3) Unity
• 4) Zero
• Discussion in forum
Solution : Imagine now your voltage amplifier taking the part of the source in the first part and a load resistance connected to its o/p with its o/p impedance acting like Rs. Rs and the load now form a voltage divider The lesser the Rs, the better, full voltage is available to the load. So, the ideal case: Zin = infinity, Rs =0

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• ( 6 ) Which among the following is an output provided by transresistance amplifier?

• 1) Output current proportional to signal voltage
• 2) Output voltage proportional to signal current
• 3) Output voltage proportional to input voltage
• 4) Output current proportional to signal current
• Discussion in forum
Answer : 4) Output current proportional to signal current
Solution : A transresistance amplifier outputs a voltage proportional to its input current. The transresistance amplifier is often referred to as a transimpedance amplifier, especially by semiconductor manufacturers

discussion

Answer : 4) Output current proportional to signal current

• ( 7 ) Stability of a transfer gain is generally defined as the reciprocal of _______

• 1) Resistivity
• 2) Conductivity
• 3) Sensitivity
• 4) Desensitivity
• Discussion in forum
Solution : Stability of a transfer gain is generally defined as the reciprocal of Sensitivity.

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• ( 8 ) Miller's theorem is applicable in a single stage CE hybrid π model in order to deal with ________

• 1) Series combination of CC and r'bc
• 2) Series combination of Ce and r'be
• 3) Parallel combination of CC and r'bc
• 4) Parallel combination of Ce and r'be
• Discussion in forum
Answer : 3) Parallel combination of CC and r'bc
Solution : Miller's theorem is applicable in a single stage CE hybrid π model in order to deal with Parallel combination of CC and r'bc.

discussion

Answer : 3) Parallel combination of CC and r'bc

• ( 9 ) Fidelity is nothing but an ability of amplifier to reproduce ________

• 1) Input signal without any distortion
• 2) Output signal without any distortion
• 3) Phase shift signal
• 4) Amplitude shift signal
• Discussion in forum
Answer : 1) Input signal without any distortion
Solution : Fidelity is nothing but an ability of amplifier to reproduce input signal without any distortion.

discussion

Answer : 1) Input signal without any distortion

• ( 10 ) What should be the level of input resistance to allow the occurrence of source loading in common base amplifier configuration?

• 1) Low
• 2) High
• 3) Moderate
• 4) Stable
• Discussion in forum
Solution : As per the configuration of CB amplifier, it is obvious that its input resistance is very low whereas its output resistance is extremely high.
However, the lower value of input resistance allows the provision of source loading in common base amplifier circuit.
Thus, there is no current amplification due to unity current gain. These all reasons ultimately contribute to high level of voltage gain.

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