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

1.  fT=1.64 X 108 Hz and fβ=1.47 x 1010Hz

2.  fT=1.47 X 1010 Hz and fβ=1.64 x 108Hz

3.  fT=1.33 X 1012 Hz and fβ=1.47 x 1010Hz

4.  fT=1.47 X 1010 Hz and fβ=1.33 x 1012Hz

4

fT=1.47 X 1010 Hz and fβ=1.33 x 1012Hz

Explanation :
No Explanation available for this question

# A 4 bit ripple counter and a 4 bit synchronous counter are made by flips flops having a propagation delay of 10 ns each. If worst case delay in the ripple counter and the synchronous counter be R and S respectively, then

1.  R = 10 ns, S= 40 ns

2.  R = 40 ns, S = 10 ns

3.  R = 10 ns, S = 30 ns

4.  R = 30 ns, S = 10 ns

4

R = 40 ns, S = 10 ns

Explanation :
No Explanation available for this question

# The Resistance seen by the source VS is

1.   258Ω

2.  1258Ω

3.  93Ω

4.  100Ω

4

1258Ω

Explanation :
No Explanation available for this question

# A 4 bit modulo-6 ripple counter uses JK flip-flop. If propagation delay of each FF is 50 ns, then maximum clock frequency that can be used is equal to

1.  5 MHz

2.  10 MHz

3.  4 MHz

4.  20 MHz

4

5 MHz

Explanation :
No Explanation available for this question

# The lower cut-off frequency due to C2 is

1.   33.99 Hz

2.  27.1 Hz

3.  13.6 Hz

4.  16.9 Hz

4

27.1 Hz

Explanation :
No Explanation available for this question

# The output Qn of a J-K flip-flop is zero. It change to 1 when a clock pulse  is applied. The input Jn and Kn are respectively

1.  1 and X

2.  0 and X

3.  X and 0

4.  X and 1

4

1 and X

Explanation :
No Explanation available for this question

# To realize the given truth table form thecircuit shown in the figure, the input to J in terms of A and B would have to be A B Qn+1 J 0 0 Qn 0 0 1 1 1 1 0 Qn 0 1 1 0 X

1.

2.

3.   B

4.  AB

4

B

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

32

Explanation :
No Explanation available for this question

# The circuit given int hefigure is to be used to implement the function Z= f(A,B) = B What values should be selected for I and J

1.  I =0 J =B

2.  I = 1 J = B

3.  I =B  J =1

4.   I =   J = 0

4

I = 1 J = B

Explanation :
No Explanation available for this question

# The ideal Op-Amp has the following characteristics

1.   Ri=∞, A=∞, R0=0

2.   Ri=∞, A=∞, R0=0

3.  Ri=∞, A=∞, R0=0

4.  Ri=∞, A=∞, R0=0

4