# A three-phase squirrel cage induction motor has a starting torque of 150 % and a maximum torque of 300 % with respect to rated torque at rated voltage and rated frequency. Neglect the stator resistance and rotational losses. The value of slip for maximum torque is

1.  13.48 %

2.  16.24 %

3.  18.92 %

4.  26.79 %

4

26.79 \%

Explanation :
No Explanation available for this question

# The matrix A given below is the node incidence matrix of a network. The columns correspond to branches of the network while the rows correspond to nodes. Let V = [v1 v2 ... v6]T denote the vector of branch voltages while I = [i1 i2.... i6]T that of branch currents. The vector E = [e1 e2 e3 e4]T denotes the vector of node voltages relative to a common ground. Which of the following statements is true

1.  The equations v1 - v2 + v3 = 0, v3 + v4 - v5 = 0 are KVL equations for the network for some loops

2.  The equations v1 - v3 - v6 = 0, v4 + v5 - v6 = 0 are KVL equations for the network for some loops

3.  E = AV

4.  AV = 0 are KVL equations for the network

4

E = AV

Explanation :
No Explanation available for this question

# An isolated 50 Hz synchronous generator is rated at 15 MW which is also the maximum continuous power limit of its prime mover. It is equipped with a speed governor with 5% droop. Initially, the generator is feeding three loads of 4 MW each at 50 Hz. One of these loads is programmed to trip permanently if the frequency falls below 48 Hz. If an additional load of 3.5 MW is connected then the frequency will settle down to

1.  49.417 Hz

2.  49.917 Hz

3.  50.083 Hz

4.  50.583 Hz

4

50.083 Hz

Explanation :
No Explanation available for this question

# Which one of the following statements regarding the INT (interrupt) and the BRQ (but request) pins in a CPU is true

1.  The BRQ pin is sampled after every instruction cycle, but the INT is sampled after every machine cycle

2.  Both INT and BRQ are sampled after every machine cycle

3.  The INT pin is sampled after every instruction cycle, but the BRQ is sampled after every machine cycle

4.  Both INT and BRQ are sampled after every instruction cycle

4

The BRQ pin is sampled after every instruction cycle, but the INT is sampled after every machine cycle

Explanation :
No Explanation available for this question

# A bridge circuit is shown in the figure below. Which one of the sequences given below is most suitable for balancing the bridge

4

Explanation :
No Explanation available for this question

# If an autotransformer is used for reduced voltage starting to provide 1.5 per unit starting torque, the autotransformer ratio (%) should be

1.  57.77 %

2.  72.56 %

3.  78.25 %

4.  81.33 %

4

78.25 \%

Explanation :
No Explanation available for this question

# If a star-delta starter is used to start this induction motor, the per unit starting torque will be

1.  0.607

2.  0.816

3.  1.225

4.  1.616

4

0.816

Explanation :
No Explanation available for this question

# If a starting torque of 0.5 per unit is required then the per unit starting current should be

1.  4.65

2.  3.75

3.  3.16

4.  2.13

4

3.16

Explanation :
No Explanation available for this question

# The resistance R should be

1.  4.7 k

2.  470 ?

3.  47 ?

4.  4.7 ?

4

47 ?

Explanation :
No Explanation available for this question

1.  2000 µV - s

2.  200 µV - s

3.  20 µV - s

4.  2.0 µV - s

4