# if the 3-phase balanced source in Figure 2.2 delivers 1500 W at a leading power factor of 0.844, then the value of ZL (in ohm) is approximately

1.

2.

3.

4.

4 Explanation :
No Explanation available for this question

# The Laplace transform of a continuous-time signal x(t) is X(s)=5-S/s2-s-2  If the Fourier transform of this signal exists, then x(t) is

1.  e 2t u(t)-2 e –t u(t)

2.  –e 2t u(-t)+ 2 e –t  u(t)

3.  –e  2t  u(-t)-2e –t u(t)

4.  e 2t u(-t)-2 e –t u(t)

4

e 2t u(t)-2 e –t u(t)

Explanation :
No Explanation available for this question

# If the impulse response  of  a  discrete-time  system  is h[n]=-5n u[-n-1] then the system function H(Z) is equal to

1.  -z/z-5  and the system is stable

2.  z/z-5 and the system is stable

3.  –z/z-5 and  the system is unstable

4.  z/z-5 and the system is unstable

4

z/z-5 and the system is unstable

Explanation :
No Explanation available for this question

# An amplifier using an opamp with a slew-rate SR = 1V/µsec has a gain of 40 dB. If  this  amplifier  has  to  faithfully  amplify  sinusoidal  signals  from  dc  to  20  KHz without  introducing any  slew-rate  induced distortion,  then  the  input  signal  level must not exceed

1.  795 mV

2.  395 mV

3.  79.5 mV

4.  39.5 mV

4

39.5 mV

Explanation :
No Explanation available for this question

# The  circuit  in Figure 2.6 employs positive  feedback and  is  intended  to generate sinusoidal  oscillation.  If  at  a  frequency f 0B(f)=ΔVf(f)/V0(f)=1/6  , then to sustain oscillation at this frequency

1.  R2=5R1

2.  R2=6R1

3.  R2=R1/6

4.  R2=R1/5

4

R2=R1/6

Explanation :
No Explanation available for this question

# A zener diode regulator in Figure 2.7 is to be designed to meet the specifications: IL = 10 mA, V0 = 10 V and Vin varies from 30 V to 50 V. The zener diode has Vz=10V and  Izk  (knee current) = 1 mA. For satisfactory  operation

1.  R ≤ 1800

2.  2000? ≤ R ≤ 2200?

3.  3700?≤R≤4000?

4.  R>4000?

4

2000? ≤ R ≤ 2200?

Explanation :
No Explanation available for this question

# The voltage gain AΔ=V0/Vi of the JFET amplifier shown in figure  2.8 is

1.  +18

2.  -18

3.  +6

4.   -6

4

-6

Explanation :
No Explanation available for this question

# The z-parameters Z11 and Z12 for the 2-port network in the figure,

1.  Z11= -6Ω/11;Z21= α 16Ω/11

2.  Z11= 6Ω/11;Z21= 4Ω/11

3.  Z11= -6Ω/11;Z21= -16Ω/11

4.  Z11= 4Ω/11;Z21= 4Ω/11

4

Z11= -6Ω/11;Z21= -16Ω/11

Explanation :
No Explanation available for this question

# The  gates G1  and G2  in  Figure  2.9  have  propagation  delays  of 10  nsec  and 20 nsec  respectively.  If  the  input  Vi makes  an  abrupt  change  from  logic  0  to  1  at time t = t0 then the output waveform V0 is

1.

2.

3.

4.

4 Explanation :
No Explanation available for this question

# An npn BJT has gm = 38m A/V,Cμ=10-14F,Cπ=4x10-13F,and DC current gain βn=90.For this transistor fT and fβ  are

1.  fT = 1.64x108 Hz and fβ =1.47x1010 Hz

2.  fT = 1. 47x1010 Hz and fβ =1.64x108 Hz

3.  fT = 1.33x1012 Hz and fβ =1.47x1010 Hz

4.  fT = 1.47x1010 Hz and fβ =1.33x1012 Hz

4