Question

The length of the manganese wire of the resistivity is 1 m is 1.84 x 10-6 32 m at 20 ° C. If the wire of the diameter is 3 x 10-4 m, what will be the temperature at the resistance of the wire?​

Answer 1

Given : The length of the manganese wire, l = 1m

resistivity of manganese wire, ρ = 1.84 × 10¯⁶ Ωm at 20°C.

diameter of wire, d = 3 × 10¯⁴ m

To find : resistance of wire at that temperature.

solution : using formula, R = ρl/A

here A = cross sectional area of wire

= πd²/4

= 3.14 × (3 × 10¯⁴)²/4

= 3.14 × 9/4 × 10^-8 m²

= 7.065 × 10^-8 m²

now Resistance of wire, R = (1.84 × 10¯⁶ Ωm × 1m)/(7.065 × 10^-8 m²)

= (1.84/7.065) × 10² Ω

= 0.26 × 10² Ω

= 26 Ω

Therefore the resistance of the wire at that temperature is 26 Ω.

Answer 2

Answer:

hope it helped ...........