Question: A shunt generator can self-excite:_________________?

• 1. only if the resistance of the field circuit is less than critical value
• 2. only if the resistance of the field circuit is greater than critical value
• 3. irrespective of the value of the resistance in the field circuit
• 4. none

Question: The terminal voltage of a series generator is 150 V when the load current is 5 A. If the load current is increased to 10 A, the terminal voltage will be____________?

• 1. 150 V
• 2. less than 150 V
• 3. greater than 150 V
• 4. none of the above

Question: The open circuit voltage of a compound generator is 250 V. At full load the terminal voltage____________?

• 1. will be less than 250 V
• 2. will always be 250 V
• 3. may be greater or less than 250 V
• 4. none of the above

Question: A series generator can self-excite:______________?

• 1. only if the load current is zero
• 2. only if the load current is not zero
• 3. irrespective of the value of load current
• 4. none of the above

Question: A D.C. generator works on the principle of____________?

• 1. Lenz’s law
• 2. Ohm’s law
• 3. Faraday’s law of electromagnetic induction
• 4. none of the above

Question: Stepless speed control of induction motor is possible by which of the following methods ?

• 1. e.m.f. injection in rotor eueuit
• 2. Changing the number of poles
• 3. Cascade operation
• 4. None of the above

Question: It is advisable to avoid line-starting of induction motor and use starter because__________?

• 1. motor takes five to seven times its full load current
• 2. it will pick-up very high speed and may go out of step
• 3. it will run in reverse direction
• 4. starting torque is very high

Question: When the equivalent circuit diagram of doouble squirrel-cage induction motor is constructed the two cages can be considered__________?

• 1. in series
• 2. in parallel
• 3. in series-parallel
• 4. in parallel with stator

Question: The torque developed in the cage induction motor with autostarter is___________?

• 1. k/torque with direct switching
• 2. K x torque with direct switching
• 3. K2 x torque with direct switching
• 4. k2/torque with direct switching

Question: The auto-starters (using three auto transformers) can be used to start cage induction motor of the following type__________?

• 1. star connected only
• 2. delta connected only
• 3. A and B both
• 4. none of the above