Home
Class 12
PHYSICS
Two metal wire of identical dimensions a...

Two metal wire of identical dimensions are connected in series if `sigma_(1)" and "sigma_(2)` are the conductivities of the metal wires respectively, the effective conductivity of the combination is

A

`(sigma_(1)sigma_(2))/(sigma_(1)+sigma_(2))`

B

`(2sigma_(1)sigma_(2))/(sigma_(1)+sigma_(2))`

C

`(sigma_(1)+sigma_(2))/(2sigma_(1)sigma_(2))`

D

`(sigma_(1)+sigma_(2))/(sigma_(1)sigma_(2))`

Text Solution

Verified by Experts

The correct Answer is:
B

`R_(eq)=R_(1)+R_(2)`
`rho(2L)/(A)=rho_(1)(L)/(A)+rho_(2)(L)/(A)`
`2rho=rho_(1)+rho_(2)`
`(2)/(sigma)=(1)/(sigma_(1))+(1)/(sigma_(2))`
`(2)/(sigma)=(sigma_(1)+sigma_(2))/(sigma_(1)sigma_(2))`
`sigma=(2sigma_(1)sigma_(2))/(sigma_(1)+sigma_(2))`
Promotional Banner

Similar Questions

Explore conceptually related problems

Two metal wires of identical dimesnios are connected in series. If sigma_(1) and sigma_(2) are the conducties of the metal wires respectively, the effective conductivity of the combination is

Two metal wires of identical dimesnios are connected in series. If sigma_(1) and sigma_(2) are the conducties of the metal wires respectively, the effective conductivity of the combination is

A copper wire and an iron wire, each having an area of cross-section A and lengths L_(1) and L_(2) are joined end to end. The copper end is maintained at a potential V_(1) and the iron end at a lower potential V_(2) . If sigma_(1) and sigma_(2) are the conductivities of copper and iron respectively, then the potential of the junction will be

Two bar of identical dimensions are kept as shown in figure. If K_1 and K_2 are their coefficients of thermal conductivities, then equivalent K

Electrical conductivies of Ge and Na are sigma_(1) and sigma_(2) respectively. If these substances are heard, then

A metal wire of length L_1 and area of cross section A is attached to a rigid support. Another metal wire of length L_2 and of the same cross sectional area is attached to the free end of the first wire. A body of mass M is then suspended from the free end of the second wire, if Y_1 and Y_2 are the Young's moduli of the wires respectively the effective force constant of the system of two wires is

A metal wire of length L_1 and area of cross section A is ttached to a rigid support. Another metal wire of length L_2 and of the same cross sectional area is attached to the free end of the first wire. A body of mass M is then suspended from the free end of the second wire, if Y_1 and Y_2 are the Young's moduli of the wires respectively the effective force constant of the system of two wires is

Two teams A and B have the same mean and their coefficients of variance are 4, 2 respectively. If sigma_(A), sigma_(B) are the standard deviations of teams A, B respectively then the relation between item is

Two wires of same dimension but resistivity p_(1) and p_(2) are connected in series. The equivalent resistivity of the combination is

Two wires of the same dimensions but resistivities p_(1) and p_(2) are connected in series. The equivalent resistivity of the combination is