Home
Class 12
PHYSICS
A metal wire of circular cross section h...

A metal wire of circular cross section has a resistance `R_1`.The wire is now stretched without breaking so that its length is doubled and the density is assumed to remain the same IF the resistance of the wire now becomes `R_2` then `R_2:R_1` is

A

`1:1`

B

`1:2`

C

`4:1`

D

`1:4`

Text Solution

Verified by Experts

The correct Answer is:
C
IF the length of the wire is l and its cross sectional area is A, volume of the wire,V=IA=constant.
Then `A=V/l`
Now , from the relation `R=rho1/A`,
`R_1/R_2=l_1/l_2.A_2/A_1=l_1/l_2.(V//l_2)/(V//l_1)=(l_1/l_2)^2=(1/2)^2=1/4`
or,`R_2/R_1=4/1=4:1`
Promotional Banner

Topper's Solved these Questions

  • CURRENT ELECTRICITY

    CHHAYA PUBLICATION|Exercise EXAMINATION ARCHIVE WITH SOLUTIONS(JEE MAIN)|4 Videos

  • CURRENT ELECTRICITY

    CHHAYA PUBLICATION|Exercise EXAMINATION ARCHIVE WITH SOLUTIONS(AIPMT)|2 Videos

  • CURRENT ELECTRICITY

    CHHAYA PUBLICATION|Exercise EXAMINATION ARCHIVE WITH SOLUTIONS(WBCHSE)|18 Videos

  • COMMUNICATION STSTEM

    CHHAYA PUBLICATION|Exercise CBSE SCANNER|28 Videos

  • DIFFRACTION AND POLARISATION OF LIGHT

    CHHAYA PUBLICATION|Exercise CBSE SCANNER|27 Videos

Similar Questions

Explore conceptually related problems

A metallic wire of specific resistance s is stretched in such a way that its length is doubles and area of cross section is halved Then the specific resistance of the wire will be

A metallic wire has a definite resistance . IF the wire is stretched in such a way that its length becomes doubled then what will be the resistance of the wire? Consider the volume and the resistivity of the wire remains unchanged.

A wire of resistance 10 Omega is stretched so that its length is thrice its original length. The new resistance is-

If a wire is stretched to double its length, find the new resistance if the original resistance be R.

A metal write of resistance 6 ohm is stretched so that is length becomes double of its original length. What would be the final resistance?

A uniform metal wire of resistance R is stretched to twice its length. Now this wire is halved, and the two halves are connected in parallel. The equivalent resistance is

A uniform metal wire of resistance R is stretched to twice its length. Now this wire is halved and the two part are connected in parallel. The equivalent resistance is-

A metal wire has a resistances of 5 Omega . If its length is doubled by stretching,what would be its resistance? Suppose the volume and resistivity of the wire do not change.

A wire has resistance 5Omega . If it is stretched to increase the Length by 10% then what will be its final resistance?