Current Electricity Charging Discharging Of Capacitors Question 389
Question: The resistance of a coil is 4.2 W at 100o C and the temperature coefficient of resistance of its material is 0.004/o C. Its resistance at 0o C is
[KCET 1999]
Options:
A) 6.5 W
B) 5 W
C) 3 W
D) 4 W
Show Answer
Answer:
Correct Answer: C
Solution:
$ R _{t}=R _{0}(1+\alpha ,t) $
Therefore 4.2 = $ R _{0}(1+0.004\times 100)=1.4R _{0} $
Therefore $ R _{0}=3\Omega $ .
BETA
