Question

A wire having resistance R is cut to two parts then the resistance of each part will be
a.R/2
b.2R
c.3R/2
d.none

Answer 1

Are the parts equal in length?

Answer 2

Given that it asks for resistance of 'each part' and gives only one choice in each answer I guess we have to assume equal lengths.

Think about the meaning of resistance - it literally means that the current is resisted from flowing.

Do you think that electricity can flow through a very long wire more easily or less easily than a short wire?

SO if you cut a wire in half - what is likely to happen to the resistance?

Answer 3

A logical assumption MrNood.

Answer 4

Answer should be 'a' because resistance is equal to the length so if the length decreases to half of its initial length so the resistance also decreases to half.

Answer 5

@mitun

maybe it would've been better for the OP to derive that answer for himself from the leads given above.

Answer 6

BTW - Resistance is not "equal" to length - it is proportional to it

R = \rho \frac{\ell}{A},

Resistance = rho *l/A

where rho is resistivity of the material, l is length of the wire and A is cross section area of wire.

@israr000 you can derive the answer from that equation.