# A step down chopper is operated in the continuous conduction mode in steady state with a constant duty ratio D.if VO is the magnitude of the dc input voltage,the ratio is given by

1.  D

2.  1-D

3.

4.

4

D

Explanation :
No Explanation available for this question

# A two port network shown in the figure is described by the following equation I1=y11E1+Y12E2 I1=y21E1+Y22E2 The admittance parameters Y11Y12 Y22  for the network shown are

1.  0.5 mho,1 mho,2 mho and 1 mho respectively

2.  1/3 mho,-1/6 mho,-1/6 mho and 1/3 mho respectively

3.  0.5 mho,0.5 mho,1.5 mho and 2 mho respectively

4.   -2/5 mho,-3/7 mho,3/7 mho and 2/5 mho respectively

4

1/3 mho,-1/6 mho,-1/6 mho and 1/3 mho respectively

Explanation :
No Explanation available for this question

# In the circuit shown in figure what value of C will cause a unity power factor  at the ac source

1.  68.1μF

2.  165 μF

3.  0.681μF

4.  6.81μF

4

68.1μF

Explanation :
No Explanation available for this question

# A first order,low pass filter is given with R=50 and C=5μF.what is the frequency at which the gain of the voltage transfer function of the filter is 0.25?

1.  4.92 kHz

2.  0.49 kHz

3.  2.46 kHz

4.  24.6 kHz

4

2.46 kHz

Explanation :
No Explanation available for this question

# A series R-L-C circuit has R=50,L=100 μH and C=1 μF the lower half power frequency of the circuit is

1.  30.55 kHz

2.   3.055 kHz

3.  51.92 kHz

4.  1.92 kHz

4

51.92 kHz

Explanation :
No Explanation available for this question

# A 200 V,2000 rpm,10 A separately excited dc motor has an armature resistance of 2,rated dc voltage is applied to both the armature and field winding of the motor.if the armature drawn 5A from the source the torque developed by the motor is

1.  4.30 Nm

2.  4.77 Nm

3.  0.45 Nm

4.  0.50 Nm

4

4.77 Nm

Explanation :
No Explanation available for this question

# The rotor of a three phase 5 Kw,400 V,50 Hz slip ring induction motor is wound for 6 poles while its stator is wound for 4 poles.the approximate average no load steady state speed when this motor is connected to 400 V,50 Hz supply is

1.  1500 rpm

2.  500 rpm

3.  0 rpm

4.  1000 rpm

4

0 rpm

Explanation :
No Explanation available for this question

# The flux per pole in a synchronous motor with the field circuit ON and the stator disconnected from the supply is found to be 25 m Wb.when the stator is connected to the rated supply with the field excitation unchanged,the flux per pole in the machine is found to be 20 mWb while the motor is running on no load.Assuming no load losses to be zero,the no load current down by the motor from the supply

1.  lags the supply voltage

3.  is in phase with the supply voltage

4.  is zero

4

Explanation :
No Explanation available for this question

# An 11 V pulse of 10 μs duration is applied to the circuit shown in the figure.Assuming that  the capacitor is completely discharged prior to applying the pulse,the peak value of the capacitor voltage is

1.  11 V

2.  5.5 V

3.  6.32 V

4.  0.96 V

4

6.32 V

Explanation :
No Explanation available for this question

# The output voltage(Vo) of the schmitt trigger shown in the figure.swings between +15v and -15v.Assume that the operational amplifier is ideal,the output will change from +15v and -15v.when the instantaneous value of the input sine wave is

1.  5V in the positive slope only

2.  5V in the negative slope only

3.  5V in the positive and negative slopes only

4.  3V in the positive and negative slopes only

4