Junior Engg. Paper Set

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Q1:- When the current through the coil of an electromagnet reverses the 

1. direction of the magnetic field remains unchanged 
2. direction of  the magnetic field reverses
3. magnetic field expands
4. magnetic field collapses

ANSWER:- 2

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Q2:- Thevenin's theorem can not be applied to

1. passive circuit
2. active circuit
3. linear circuit
4. nonlinear circuit

ANSWER:- 4

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Q3:- A 10 pole 25 hz alternator is directly couple to and is driven by 60 hz synchronous motor then the number of poles in a synchronous motor are

1. 24 poles
2. 12 poles
3. 48 poles
4. none

ANSWER:- 1

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Q4:- The motor used on small lathes is usually

1. universal motor
2. single phase capacitor run
3. dc shunt motor
4. 3-phase synchonous

ANSWER:- 2

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Q5:-In dc operation of flourescent tube the life of the tube 

1. may increase or decrease
2. remain same
3. increases by about 80 % as that with ac operation
4. decreases by about 80 % as that with ac operation

ANSWER:- 4

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