Objective Questions on DC Generator for Electrician Trade
| Sr. No. | Questions with options |
| 1 | Which rule is used to find the direction of induced emf in D.C generator?
(a) Cork screw rule (b) Right hand palm rule (c) Fleming’s left hand rule (d) Fleming’s right hand rule Ans –(d) |
| 2 | Which energy is converted into electrical energy by generator?
(a) Heat (b) Kinetic (c) Chemical (d) Mechanical Ans – (d) |
| 3 | What is the principle of D.C generator?
(a) Cork screw rule (b) Fleming’s left hand rule (c) Fleming’s right hand rule (d) Faradays laws of electromagnetic induction Ans – (d) |
| 4 | Which rule is used to find direction of magnetic field?
(a) Cork screw rule (b) Right hand palm rule (c) Fleming’s left hand rule (d) Fleming’ right hand rule Ans – (d) |
| 5 | How many parallel paths in duplex lap winding of a 4 pole DC generator?
(a) 4 (b) 6 (c) 8 (d) 12 Ans – (c) |
| 6 | How interpoles are connected in a DC generator?
(a) In series with armature (b) In parallel with armature (c) In series with shunt field (d) In parallel with shunt field Ans –(a) |
| 7 | What is the necessity of residual magnetism in a self excited DC generator?
(a) Build up the voltage (b) Reduce the field current (c) Reduce armature current (d) Maintain constant output voltage Ans – (a) |
| 8 | Which are the two points that the brush contact resistance measured in DC machine?
(a) Resistance between the opposite brushes (b) Resistance between brush and commutator (c) Resistance between brush and armature (d) Resistance between brush and armature conductors Ans-(c) |
| 9 | What is the name of the compound generator, if the shunt field is connected in parallel with armature?
(a) Long shunt compound (b) Cumulative compound (c) Differential compound (d) Short shunt compound Ans – (d) |
| 10 | Why the armature core of a DC generator is laminated?
(a) Reduce the copper loss (b) Reduce the friction loss (c) Reduce the hysteresis loss (d) Reduce the eddy current loss Ans –(d) |
| 11 | Why the armature resistance of a D.C generator is very low?
(a) Reduce armature current (b) Reduce armature voltage drop (c) Run armature with less weight (d) Reduce the temperature of armature Ans – (b) |
| 12 | Why the D.C generator should run in clockwise direction only?
(a) Protect brushes from damage (b) Protect the residual magnetism (c) Avoid short circuit in armature (d) Avoid over loading of generator Ans – (b) |
| 13 | Why compensating winding is provided in large DC generators?
(a) Connect more loads (b) Reduce commutation effect (c) Neutralize armature reaction effect (d) Increase the efficiency of generator Ans – (c) |
| 14 | What is the reason for DC generator fails to build up voltage
(a) Loose brush contact (b) Armature resistance is more (c) Field resistance is above critical resistance (d) Prime mover is running at above rated speed Ans-(c) |
| 15 | What is the name of generator, if its field is connected in parallel with armature?
(a) Shunt generator (b) Series generator (c) Compound generator (d) Self excited generator Ans – (a) |
| Data Collected By – Rashmi | |
| Published On – 31st May 2022 | |
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