Question

the wire of 3 ohm resistor and 15 centimetre restricted to 45 CM calculate the new resistance area new resistance and resistivity ask you the wire has a uniform cross sectional area​

Answer 1

resistance R=3ohm

length L=15cm=0.15m

R=resistivity L/A

3=rho 0.15/A

rho /A=3/0.15………1

new length L1=45cm=0.45m

The area is same then

New resistance R1 =rho L1/A

R1=3/0.15 x L1

R1=3x0.45/0.15

R1=9 Ohm