# A Unity negative feedback amplifier is having two open loop poles at ω1 and ω2, If ω2=100 ω1 then open loop mid band gain A0 for obtaining quality factor of Q = 0.5 is

1.  A0 = 49

2.  A0 = 25.5

3.  A0 = 24.5

4.  A0 = 51

4

A0 = 24.5

Explanation :
No Explanation available for this question

# Which of the following statement is correct regarding an amplifier with single pole transfer function.

1.  The gain bandwidth product with feedback is greater than gain-bandwidth product without feedback

2.  The gain-bandwidth product with feedback is equal to gain bandwidth product without feedback.

3.  The gain bandwidth product with feedback is less than gain bandwidth product without feedback

4.  The gain bandwidth product with feedback is never equal to gain bandwidth product without feedback.

4

The gain-bandwidth product with feedback is equal to gain bandwidth product without feedback.

Explanation :
No Explanation available for this question

# Which of the following correctly represents relating to thermal runaway in a transistor

1.  It occurs in active mode due to heating of the transistor

2.  It occurs in saturation mode due to due to change in reverse collector saturation current due to rise in temperature

3.  It occurs in active mode due to due to change in β which increases with temperature

4.   It occurs in active mode due to change in reverse collector saturation current due to rise in temperature

4

It occurs in active mode due to change in reverse collector saturation current due to rise in temperature

Explanation :
No Explanation available for this question

# Which of the following represents correct output wave form for the input shown below (consider ideal diode)

1.

2.

3.

4.

4

Explanation :
No Explanation available for this question

# In real life a feedback loop which has a loop gain exactly equal to 1 at a particular frequency will never cause sustained oscillations because

1.  This is not a Barkhausen criterion

2.   Non-linearity of the circuit will dampen the oscillation

3.  This will violate the law of consecration of energy

4.  Variations of the circuit parameter value due to temperature, age etc. will make the gain either larger or smaller than unity.

4

Variations of the circuit parameter value due to temperature, age etc. will make the gain either larger or smaller than unity.

Explanation :
No Explanation available for this question

# The condition to avoid thermal run away in a transistor is (where notation have their usual meaning)

1.  VCE > VCC/2

2.  ∂PC/∂Tj < ∂PD/∂Tj

3.   ∂PC/∂Tj < 1/θ

4.  Both b & c

4

Both b & c

Explanation :
No Explanation available for this question

# Thermal run away in a transistor circuit refers to the phenomenon of

1.  Uncontrolled increase temperature due to positive feedback caused by self heating and increase in  collector currents with increasing temperature

2.  Reduction in thermal resistance with increasing temperature

3.  Change in slope of the thermal load line with changing temperatures

4.  Uncontrolled increase temperature due to avalanche multiplication

4

Uncontrolled increase temperature due to positive feedback caused by self heating and increase in  collector currents with increasing temperature

Explanation :
No Explanation available for this question

# An Op-Amp circuit is shown in the figure. The output voltage V0 for an input Vi = [2+sin(100t)]V is

1.  3/2 Sin(100)

2.  3 sin (100t)

3.  2 sin(100t)

4.  3 sin(100t)+1/2 a

4

3/2 Sin(100)

Explanation :
No Explanation available for this question

# The coupling capacitors are used in amplifier circuit to

1.  Allow AC & DC voltages to be applied to the transistor without affecting each other

2.  Increases coupling between the input and output AC signals

3.   Couple the base and collector currents of the transistor

4.  Increase the DC voltage gain

4

Allow AC & DC voltages to be applied to the transistor without affecting each other

Explanation :
No Explanation available for this question

1.

2.

3.

4.

4