Question: A dc series motor should not be started on no load because it would___________?

• 1. not develop starting torque
• 2. fail to start without load
• 3. run at dangerously high speed
• 4. draw more current without producing sufficient torque

Question: In a DC motor the inter-pole winding is connected in________________?

• 1. series with field winding
• 2. series speed armature winding
• 3. parallel big field winding
• 4. parallel with armature winding

Question: Armature reaction in dc motor results___________?

• 1. decrease in speed
• 2. increase in speed
• 3. short circuit
• 4. open circuit

Question: Which of the following test can be performed on DC series motor?

• 1. Swinburne test
• 2. Hopkinson test
• 3. Brake test
• 4. Field test

Question: Ward Leonard method of speed control is basically a______________?

• 1. field control method
• 2. armature controlled method
• 3. field diverter
• 4. frequency control method

Question: The purpose of providing dummy coils in a generator is__________________?

• 1. to reduce eddy current losses
• 2. to enhance flux density
• 3. to amplify voltage
• 4. to provide mechanical balance for the rotor

Question: If residual magnetism is present in a D.C. generator, the induced e.m.f. at zero speed will be____________?

• 1. zero
• 2. small
• 3. the same as rated voltage
• 4. high

Question: Armature reaction in a generator results in_____________?

• 1. demagnetisation of leading pole tip and magnetisation of trailing pole tip
• 2. demagnetisation of trailing pole tip and magnetisation of leading pole tip
• 3. damagnetising the center of all poles
• 4. magnetising the center of all poles

Question: Following energized winding of a D.C. machine should not be opened as it would produce high inductive voltage which may be dangerous to personnel and may cause its own insulation failure.

• 1. Series field
• 2. Compensating field
• 3. Inter pole field
• 4. Shunt field

Question: Which generator would you prefer for feeding long D.C. transmission lines ?

• 1. Series generator
• 2. Shunt generator
• 3. Over compound generator
• 4. Flat compound generator