Electric Machine Daily Quiz #12

For a 50 Hz system, the value of P.N for a synchronous machine will be (where P = number of poles and N = speed in rpm)-

1. 5000
2. 6000
3. 1500
4. 1800

Steam turbine works most economically at-

1. 1500 rpm
2. 3000 rpm
3. 4000 rpm
4. 6000 rpm

Which statement is true-

1. Number of poles is independent, Speed is dependent variable
2. Speed is independent, Number of poles is dependent variable
3. Number of poles and Speed, both are independent variables
4. Number of poles and Speed, both are dependent variables

Salient Pole machine is preferred for-

1. P>4 
2. P<4
3. P>10
4. P<10

Direct axis reactance Xd and Quadrature axis reactance Xq are related by-

1. Xd> Xq
2. Xq > Xd
3. Xd = Xq
4. None