Home
Class 12
PHYSICS
When 115 V is applied across a wire of l...

When 115 V is applied across a wire of length 10m and radius 0.3 mm, the current density is `1.4 xx 10^4 A m^2`. The resistivity of the wire is:

A

`4.1 xx 10^4 Omega m`

B

`8.2 xx 10^(-4) Omega m`

C

`16.4 xx10^4 Omega m`

D

`2.1 xx 10^4 Omega m`

Text Solution

Verified by Experts

The correct Answer is:
B
`E = V/l`
`:." current density J" = V/(rho l)`
` (115)/(1.4 xx 10^4 xx 10)`
` = 8.2 xx 10^(-4) Omega` m
Promotional Banner

Similar Questions

Explore conceptually related problems

A wire of length 1 m and radius 0.1mm has a resistance of 100(Omega) .Find the resistivity of the material .

The voltage across a wire is (100pm5)V and the current passing through it is (10pm0.2) A. Find the resistance of the wire.

The resistance of a wire of length 10 cm is 2 ohm, then its conductance is . . . . . . . . . .

A copper wire of length 2 m and area of cross-section 1.7xx10^(-6)m^(2) has a resistance of 2xx10^(-2)Omega. The resistivity of copper is

Find the resistance of a hollow cylindrical conductor of length 1.0m and inner and outer radii 1.0mm and 2.0mm respectively. The resistivity of the material is 2.0xx10^(-8)(Omega)m .

A load of 4.0 kg is suspended from a ceiling through a steel wire of length 20 m and radius 2.0 mm. It is found that the length of the wire increases by 0.031 mm as equilibrium is achieved. Find Young modulus of steel. Take g=3.1pims^-2

The voltage across a wire is (100+-5)v and the current passing through it is (10+-0.2)A .