Question

Resistance of wire is 100 ohm.Now if material is double folded then then evalute new resistance of the wire and heat ratio(I just need heat ratio)correct
Answer will be marked brainliest

Answer 1

.area of cross section will get doubled.

∴ Let the resistance of the wire originally 'R' of length 'L' and area of cross-section 'A' with resistivity of material is 'p',

Then

R = p l/A = 100 ohm

Now, for new arrangement,

p' = p

l' = l

A' = 2A

Thus, 

R' = p' l'/A' = pl/2A = 1/2R = 1/2× 100= 50Ω.

Ratio of Heat is I^2×100×t:I^2×50×t

100:50

Is 2:1

Hope this helps .....