The resistance of a wire at 20 ° C is 20 Ω and 500 ° C is 60 Ω . At which temperature, its resistance will be 25 Ω ?

Step-by-step solution

We have, R t = R 0   1 + α t Here, 20 = R 0   1 + 20 α 60 = R 0   1 + 500 α ⇒       60 20 = R 0   1 + 500 α R 0   1 + 20 α 3 = 1 + 500   α 1 + 20   α ⇒   3   1 + 20   α = 1 + 500   α ⇒   3 + 60 α = 1 + 500 α ⇒   440   α = 2 ⇒   α = 2 440 = 1 220 I ° C Also given R t = 25   ° C ,   t =   ? Now, 20 25 = R 0 &#1