# A stable and casual system is described by the difference equation y(n) + y(n-1)/4 – y(n-2)/8 = - 2x(n) + 5x(x – 1)/4.The system impulse response is

1.  h(n) = (1/4)n u(n) – 3(-1/2)n u(n)

2.  h(n) = (1/4)n u(n) – 3u(n)

3.  h(n) = u(n)

4.  None of these

4

h(n) = (1/4)n u(n) – 3u(n)

Explanation :
No Explanation available for this question

1.

2.

3.

4.  None of these

4

Explanation :
No Explanation available for this question

# The time constant of the Network shown in the figure is

1.  2 RC

2.  3 RC

3.  RC/2

4.  2 RC/3

4

2 RC/3

Explanation :
No Explanation available for this question

# A 35 V source connected to a series circuit at 600 ohms and R shown. if a voltmeter at internal resistance 1.2 kilo ohms is connected across 600 ohm resistor it reads 5 V. The value of R is

1.  1.2 kΩ

2.  2.4 kΩ

3.  3.6 kΩ

4.  7.2 kΩ

4

2.4 kΩ

Explanation :
No Explanation available for this question

# The energy stored in the magnetic field at a solenoid 30 cm long and 3 cm diameter wound with 1000 turns of wire carrying a current at 10 A ,is

1.   0.015 Joule

2.  0.15 Joule

3.  0.5 Joule

4.  1.15 Joule

4

0.15 Joule

Explanation :
No Explanation available for this question

# Two coils having equal resistance but difference inductance's are connected in series .The time constant of the series combination is the

1.  sum of the time constants of the individuals coils

2.  average of the time constants of the individual coils

3.  geometric mean of the time constant of the individuals coils

4.  product of the time constants of the individual coils

4

average of the time constants of the individual coils

Explanation :
No Explanation available for this question

# At a certain current , the energy stored in iron cored coils 1000 J and its copper loss 2000 W. The time constant (in seconds ) of the coil is

1.  0.25

2.  0.5

3.  1.0

4.  2.0

4

1.0

Explanation :
No Explanation available for this question

# The current wave form in a pure resistor at 10Ω is shown in the given figure. power dissipated in the resistor is

1.  7.29 W

2.  52.4 W

3.  135 W

4.  270 W

4

270 W

Explanation :
No Explanation available for this question

# A series RLC Circuit consisting of R = 10 ohms, XL = 20 ohms is connected across an AC supply of 100 V (rms) . The magnitude and phase angle (with reference to supply voltage)of the voltage across the inductive coil are respectively

1.  100 V , 900

2.  100 V , - 900

3.  200 V , 900

4.  200 V , - 900

4

200 V , - 900

Explanation :
No Explanation available for this question

1.  ∞

2.  1 J

3.  1/2 J

4.  0

4