A $3\,^oC$ rise in temperature is observed in a conductor by passing a certain current. When the current is doubled, the rise in temperature will be ............. $^oC$
A$15$
B$12$
C$9$
D$3$
Medium
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B$12$
b ${i^2}Rt = C\theta = 3\,C;$ $C =$ Thermal capacity
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