MULTIPLE CHOICE QUESTIONS-DC MACHINES & TRANSFORMERS - A SEC

1.In DC machine, commuataor converts

a) dc to ac b) ac to dc c) both ac to dc and dc to ac d) None of the above

2.Which type of emf is induced in the dc generator

a) Dynamically b) Static c) Electrostatic d) Magentic

3.The critical resistance of the dc generator is the resistance of(a) Armature (b) Field (c) Load (d) Brushes

4.Fleming's Left hand rule is applicable to:

a) DC generator b) DC motor c) Transformer d) Alternator

5.The armature of the dc machines are laminated to reduce:

a) Eddy current loss b)Hysteresisloss c) copper loss d) field flux loss

6.The function of brushes in a DC Generator is to:

a) Collect the current from the commutator and supply it to external circuitb) Prevent the sparkingc) Helps to provide good commutation by offering smooth surfaced) Provide continuity between adjacent commutator segments

7.Voltage equation of a dc motor isA. V = Eb + IaRa B. Eb= V + IaRa C. V = Eb/IaRa D. V = Eb + Ia2Ra

8.which of the following motor has the constant speed?A. Series motor B. Shunt motor C. Cumulatively compound motorD. All of the above

9.A DC series motor is best for drivingA. Lathes B. Cranes and hoists C. Shears and punches D. Machine tools

10.In a DC series motor increasing the load current willA. Decrease the speed B. Increase the speedC. Better commutation D. Increase the back emf

MULTIPLE CHOICE QUESTIONS-DC MACHINES & TRANSFORMERS - A SEC

1.In DC machine, commuataor converts

a) dc to ac b) ac to dc c) both ac to dc and dc to ac d) None of the above

2.Which type of emf is induced in the dc generator

a) Dynamically b) Static c) Electrostatic d) Magentic

3.The critical resistance of the dc generator is the resistance of(a) Armature (b) Field (c) Load (d) Brushes

4.Fleming's Left hand rule is applicable to:

b) DC generator b) DC motor c) Transformer d) Alternator

5.The armature of the dc machines are laminated to reduce:

b) Eddy current loss b)Hysteresisloss c) copper loss d) field flux loss

6.The function of brushes in a DC Generator is to:

a) Collect the current from the commutator and supply it to external circuitb) Prevent the sparkingc) Helps to provide good commutation by offering smooth surfaced) Provide continuity between adjacent commutator segments

7.Voltage equation of a dc motor isA. V = Eb + IaRa B. Eb= V + IaRa C. V = Eb/IaRa D. V = Eb + Ia2Ra

8.which of the following motor has the constant speed?A. Series motor B. Shunt motor C. Cumulatively compound motorD. All of the above

9.A DC series motor is best for drivingA. Lathes B. Cranes and hoists C. Shears and punches D. Machine tools

10.In a DC series motor increasing the load current willA. Decrease the speed B. Increase the speedC. Better commutation D. Increase the back emf