# A sequential circuit using D flip-flop and logic gates is shown in Fig.P2.9, where X and Y are the inputs and Z is the output. The circuit is

1.  S – R Flip-Flop with inputs X = R and Y = S

2.  S – R Flip-Flop with inputs X = S and Y = R

3.  J – K Flip-Flop with inputs X = J and Y = K

4.  J – K Flip-Flop with inputs X = K and Y = J

4

S – R Flip-Flop with inputs X = S and Y = R

Explanation :
No Explanation available for this question

# The  contents  of  Register  (B)  and  Accumulator  (A)  of  8085 microprocessor  are 49H and 3AH respectively. The contents of A and the status of carry flag (CY) and sign flag (S) after executing SUB B instructions are

1.  A = F1, CY = 1, S =1

2.  A = 0F, CY = 1, S =1

3.  A = F0, CY = 0, S =0

4.  A = 1F, CY = 1, S =1

4

A = 1F, CY = 1, S =1

Explanation :
No Explanation available for this question

# In  Fig.P2.11,  the  J  and  K  inputs  of  all  the  four  Flip-Flops  are made  high.  The frequency of the signal at output Y is

1.  0.833 KHz

2.  1.0 KHz

3.  0.91 KHz

4.  0.77 KHz

4

0.833 KHz

Explanation :
No Explanation available for this question

# One  period  (0,T)  each  of  two  periodic  waveforms,  W1  and  W2  are  shown  in Fig.P2.12. The magnitudes of the nth Fourier series coefficients of W1 and W2, for n ≥ 1, n odd, are respectively proportional to

1.  |n -3| and |n -2|

2.  |n -2| and |n -3|

3.  |n -1| and |n -2|

4.  |n -4| and |n -2|

4

|n -3| and |n -2|

Explanation :
No Explanation available for this question

# Let  u(t)  be  the  step  function.  Which  of  the  waveforms  in  Fig.P2.13(a)  –  (d) corresponds to the convolution of u(t) – u(t – 1) with u(t) – u(t – 2)

1.

2.

3.

4.

4

Explanation :
No Explanation available for this question

# In Fig.P2.14, the steady state output voltage corresponding to the input voltage 3 + 4 sin 100t V is

1.  3+4/√2 sin(100t-π/4) V

2.  3+4√2 sin(100t-π/4) V

3.  3/2+4/√2 sin(100t+π/4) V

4.  3+4sin(100t+π/4) V

4

3+4√2 sin(100t-π/4) V

Explanation :
No Explanation available for this question

# In a digital communication system employing Frequency Shift Keying (FSK), the 0 and 1 bit are  represented by  sine waves of 10 KHz and 25 KHz  respectively. These waveforms will be orthogonal for a bit interval of

1.  45 µsec

2.  200 µsec

3.  50 µsec

4.  250 µsec

4

45 µsec

Explanation :
No Explanation available for this question

# A message m(t) band-limited to the frequency  f m has a power of  . Pm  The power of the output signal in the Fig.P2.16 is

1.   a)  Pm cosθ/2

2.  Pm /4

3.  Pm sin 2θ/2

4.  Pm cos 2θ/2

4

Pm /4

Explanation :
No Explanation available for this question

# The Hilbert transform of  cos ω1 t+sin ω2 t is

1.  sin ω1 t - cos ω2 t

2.  sin ω1 t +cos ω2 t

3.  cos ω1 t-sin ω2 t

4.  sin ω1 t+ sin ω2 t

4

sin ω1 t+ sin ω2 t

Explanation :
No Explanation available for this question

# A system described by the transfer function  H(S)= 1/s3+as2+ks+3  is stable. The constraints on α and k are

1.  α > 0, αk < 3

2.  α > 0, αk > 3

3.  α > 0, αk > 0

4.  α > 0, αk < 0

4