RRB JE 2015-28-09-2015-3 RRB Question Paper

RRB JE 2015 Question Papers

RRB JE 2015-28-09-2015-3 RRB Questions

21.
A transformer is working at its maximum efficiency. Its iron loss is 1 kW. Its copper loss will be
A.
0.2 kW
B.
0.25 kW
C.
0.5 kW
D.
1 kW
😑 View Answer Rough Work
ANSWER :
D. 1 kW
22.
For arc heating, electrodes are made up of
A.
Copper
B.
Aluminium
C.
Graphite
D.
Tungsten
😑 View Answer Rough Work
ANSWER :
C. Graphite
23.
Sodium lamps are used in
A.
Reading rooms
B.
Street Lights
C.
Auditorims
D.
Libraries
😑 View Answer Rough Work
ANSWER :
D. Libraries
24.
The fuse wire is made up of
A.
Nichrome
B.
Lead-tin alloy
C.
Copper
D.
Tungsten
😑 View Answer Rough Work
ANSWER :
B. Lead-tin alloy
25.
There are .............. Number of modulation techniques.
A.
1
B.
2
C.
3
D.
4
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ANSWER :
C. 3
26.
In frequency modulation
A.
amplitude of carrier wave remains the same.
B.
frequency of carrier wave remains constant.
C.
both frequency and amplitude of carrier waves vary.
D.
signal gets distorted.
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ANSWER :
A. amplitude of carrier wave remains the same.
27.
In mercury arc rectifier, mercury is used as
A.
cathode
B.
conducting medium
C.
ionizing medium
D.
electron accelerator
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ANSWER :
A. cathode
28.
For single phase rotary converters, when the power factor is unity, the ac to dc current ratio will be
A.
1.0
B.
0.707
C.
1.4
D.
0.5
😑 View Answer Rough Work
ANSWER :
C. 1.4
29.
When a material becomes a superconductor, its resistivity becomes
A.
very small
B.
zero
C.
about 10% of normal value
D.
about 20% of normal value
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ANSWER :
B. zero
30.
The inputs of logic gate are 0. The output is 1. The gate is
A.
NAND or XOR
B.
OR or XOR
C.
AND or XOR
D.
NOR or Ex-NOR
😑 View Answer Rough Work
ANSWER :
D. NOR or Ex-NOR