# In the circuit shown below, the knee current of the ideal Zener diode is 10 mA. To maintain 5 V across RLthe minimum value of RL in and the minimum power rating of the Zener diode in mW, respectively, are

1.  125 and 125

2.  125 and 250

3.  250 and 125

4.  250 and 250

4

125 and 250

Explanation :
No Explanation available for this question

# The following arrangement consists of an ideal transformer and an attenuator which attenuates by a factor of 0.8. An ac voltage Vwx1= 100V is applied across WX to get an open circuit voltage V YZ1 across YZ. Next, an ac voltage V YZ2= 100V is applied across YZ to get an open circuit voltage V WX2 across WX. Then, V YZ1/ V WX1,V WX2/ V YZ2 are respectively,

1.  125/100 and 80/100

2.  100/100 and 80/100

3.  100/100 and 100/100

4.  80/100 and 80/100

4

100/100 and 80/100

Explanation :
No Explanation available for this question

# Two magnetically uncoupled inductive coils have Q factors q1 and q2 at the chosen operating frequency. Their respective resistances areR1and R2. When connected in series, their effective Q factor at the same operating frequency is

1.  q1+q2

2.  (1/ q1+1/ q2)

3.  ( q+ q2)/R1+R2

4.  (q1r2+q2r1)/(r1+r2)

4

( q+ q2)/R1+R2

Explanation :
No Explanation available for this question

# The impulse response of a continuous time system is given by  The value of the step response at t=2 is

1.  0

2.  1

3.  2

4.  3

4

1

Explanation :
No Explanation available for this question

# The small-signal resistance (i.e. dVb/dId) in K offered by n-channel MOSFET M shown in thefigure below, at a bias point of VB=2V s (device data for M: device transconductance parameter  Kn=μn Cox1(W/L)=40μA/V2 , threshold voltage Vtn=1V nd neglect body effect and channel length modulation effects)

1.  12.5

2.  25

3.  50

4.  100

4

25

Explanation :
No Explanation available for this question

# The ac schematic of an NMOS common-source stage is shown in the figure below, where part of the biasing circuits has been omitted for simplicity. For the n-channel MOSFET M, the transconductance gm= 1 mA/V, and body effect and channel length modulation effect are to be neglected. The lower cutoff frequency in Hz of the circuit is approximately at

1.  8

2.  32

3.  50

4.  200

4

8

Explanation :
No Explanation available for this question

# A system is described by the differential equation  Let x(t) be a rectangular pulse given by   Assuming that y(0)=0 and  at t=0 The laplace transform of y(t) is

1.

2.

3.

4.

4

Explanation :
No Explanation available for this question

# Asystem described by a linear, constant coefficient, ordinary, first order differential equation has an exact solution given by y (t)for t>0, when the forcing function is x(t)and the initial condition isy(0). If one wishes to modify the system so that the solution becomes -2 y(t) for t> 0, we need to

1.  change the initial condition to y(o)-and the forcing function to 2x ( t)

2.  change the initial condition to 2 y(0) −and the forcing function to X( t)

3.  change the initial condition to  j√2y(0) -and the forcing function to j√2x(0)

4.  change the initial condition to 2 y (0)−and the forcing function to 2 x (t )

4

change the initial condition to 2 y (0)−and the forcing function to 2 x (t )

Explanation :
No Explanation available for this question

# Consider two identically distributed zero-mean random variables Uand V Let the cumulative distribution functions of Uand 2VbeF (X ) and G (x ) respectively. Then, for all values of x

1.  F(x)-G(x)≤0

2.  F(x)-G(x)≥0

3.  (F(x)-G(x)).x≤0

4.  (F(x)-G(x)).x≥0

4

(F(x)-G(x)).x≥0

Explanation :
No Explanation available for this question

# The DFT of a vector  [a b c d] is the vector [α  β  γ  δ ]. Consider the product The DFT of the vector [p q r s] is a scaled version of

1.  [α2   β2   γ2  δ2]

2.  [√α  √β  √γ  √δ]

3.  [α+β  β+δ  δ+γ  γ+α]

4.  [α  β  γ  δ]

4