The resistance of a coil is 4.2 ohm at 100 degree C and temperature coefficient of resistance of its material is 0.004/degree C. Its resistance at 0 degree C is -
A) 6.5 ohm
B) 3 ohm
C) 5 ohm
D) 4 ohm
Answers
Answered by
3
Answer:
Explanation:
R
T
=4.2ohm
T=100
0
C
α=0.004/
0
C
T
0
=0
0
C
ΔT=T−T
0
=100−0=100
0
C
The resistance, R
T
=R
0
(1+αΔT)
R
0
=
(1+αΔT)
R
T
R
0
=
(1+0.004×100)
4.2
=3Ω
The correct option is B
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