From measurement of the rise time of the output pulse of an amplifier whose an input is a small amplitude square wave, which of the following parameter of the amplifier can be estimated

1.  Gain-bandwidth product

2.  Slew rate

3.  Upper 3-db frequency

4.  Lower 3-dB frequency

4

Upper 3-db frequency

Explanation :
No Explanation available for this question

The input auto-correlation of RC-filter which is subjected to a white noise of spectral density η0/2 is

1.  η0[∂(t)]

2.   η0/2[∂(t)]

3.  - η0[∂(t)]

4.  -η0/2[∂(t)]

4

η0/2[∂(t)]

Explanation :
No Explanation available for this question

Thermal runway in a transistor biased in the active region is due to

1.  Heating of the transistor

2.  Changes in β which increases with temperature

3.  Base emitter voltage VBE which decreases with rise in temperature

4.  Change in reverse collector saturation current due to rise in temperature

4

Change in reverse collector saturation current due to rise in temperature

Explanation :
No Explanation available for this question

Spectral density is X(f)=k;

1.  k/πjfe cos (fe, t)

2.  k/πjf cos (fe, t)

3.  k/πjfe sin (fe, t)

4.  k/πj cos (fe, t)

4

k/πjfe cos (fe, t)

Explanation :
No Explanation available for this question

Power spectral density of stationary noise process N(f) has correlation for Rnm(t)=ke-3|t|

1.  3k/3+ω2

2.  3k/3-ω2

3.  6k/9+ ω2

4.  6k/9- ω2

4

6k/9+ ω2

Explanation :
No Explanation available for this question

White noise, for which Rxx(t)=10-28(t) is applied to a network with impulse response h(t)=4(t)3-te-41 The network’s output noise power in a 1W resistor is

1.  0.15mW

2.   0.35mW

3.   0.55mW

4.  0.95mW

4

0.35mW

Explanation :
No Explanation available for this question

If α=0.995, IE=10mA and IC0=0.5μA, then ICE0 will be

1.  25μA

2.  100 μA

3.  10.1 mA

4.  10.5 mA

4

100 μA

Explanation :
No Explanation available for this question

Output z(t)is related to input y(t) as y=√z and probability density function of the input is P(y)=e-y; 0

1.  e√z

2.  e-√z

3.  e-z

4.  ez

4

e-√z

Explanation :
No Explanation available for this question

The approximate value of input impedance of a common emitter amplifier with emitter resistance Re is given by

1.  hie+A1Re

2.  hie+(1+hie)Re

3.  hie

4.  (1+hfe)Re

4

hie+(1+hie)Re

Explanation :
No Explanation available for this question

1.  4α/ω2+4α2

2.  4α/ω2-4α2

3.  α/ω2+α2

4.  α/ω2-α2

4