Electronics and Communication Engineering - Analog Electronics

46. 

In a circuit of figure, Vs = 10 cos(ωt) power drawn by the 2Ω resistor is 4 watts. The power factor is

A. 0.3
B. 0.4
C. 0.6
D. none

Answer: Option C

Explanation:

Vs = 10 cos ωt,

Let I be the current, then P = I2 R

I is the rms current.

Prms = I2 R 4 I2 = 4 I = 2A.

Total power drawn = Vm Im cos θ

10 x 2 cos θ = 10 cos θ

Total power cannot be determine until value of R = 12 Ω is given.


47. 

The quiescent collector current IC, and collector to emitter voltage VCE in a CE connection are the values when

A. ac signal is zero
B. ac signal is low
C. ac signal is negative
D. either (a) or (b)

Answer: Option A

Explanation:

Quiescent-operation means operation when ac signal is not applied.


48. 

In the op-amp circuit of figure, V0 =

A. Vi
B. 3 Vi
C. 5 Vi
D. 0.5 Vi

Answer: Option C

Explanation:

.


49. 

Figure shows the self bias circuit for CE amplifier and its equivalent circuit. VBB and RB respectively are

A. 10 V and 4 k ohm
B. 5 V and 4 k ohm
C. 2 V and 4 k ohm
D. 2 V and 10 k ohm

Answer: Option C

Explanation:

.


« Prev   1 2 3 4 5 6 7 8 9 10