Question

i want to know its solutin in 5min​

Answer 1

(a)Resistance of 600Ω at 50°C = 600 [1+0.001 (50−20)] = 618Ω

Resistance of 300Ω at 50°C = 300 [1+0.004 (50−20)] = 336Ω

Total resistance at 20°C = 618 + 336 = 954Ω

(b)Let β be the temperature coefficient of resistivity at 50°C

Total resistance at 20°C = 600 + 300 = 900Ω

⇒954 = 900 [1+β (50−20)]

⇒β = [(954/900) −1] / 30

⇒β = 0.002 (or) 1/500

Hope this helps...    : )