Question

What should be the length of the nichrome wire of resistance 4.5 ohm ,if the length of a similar wire 60cmand resistance 2.5 ohm?

Answer 1

Answer:

Here,R1=4.5 ohmR2=2.5 ohml1=?l2=60 cmNow using,R1R2=l1l2So, l1=R1R2×l2=4.5×602.5=108 cm

Answer 2

Answer:

Let's calculate the resistance of a wire per meter:

Rpm = 2.5 ohm / 0.6 m

        = 25/6 ohm/m.

So, the length of a 4.5 ohm wire is

L = 4.5 ohm / (25/6 ohm/m)  

  = 27/25 m

  = 1.08 m.