Home
Class 12
PHYSICS
A resistance R of therimal coefficient o...

A resistance R of therimal coefficient of resistivity `alpha` is connected in parallel with a resistance 3R. Having thermal coeffiecinet of resistivity `2alpha` Find the value of `alpha_(eff)`

Text Solution

Verified by Experts

The equivalent resistance at `0^@C` is
`R_0 = (R_(10)R_(20))/(R_(10) + R_(20))` …(i)
The equivalent resistance at `t^@`C is
`R = (R_1R_2)/(R_1+R_2)` .....(ii)
But `R_1 = R_(10)(1 + alphat)` .....(iii)
`R_2 = R_(20) (1+2 alphat)` ....(iv)
and `R = R_0 (1+alpha_(eft) t)` ...(v)
Putteing the value of (i), (iii), (iv) and (v) in Eq. (ii), we have
`alpha_(eff) = (5)/(4)alpha`
Promotional Banner

Topper's Solved these Questions

  • ELECTRIC CURRENT AND CIRCUIT

    CENGAGE PHYSICS|Exercise Solved Examples|12 Videos

  • ELECTRIC CURRENT AND CIRCUIT

    CENGAGE PHYSICS|Exercise Exercise 5.1|28 Videos

  • ELECTRIC CURRENT & CIRCUITS

    CENGAGE PHYSICS|Exercise Kirchhoff s law and simple circuits|15 Videos

  • ELECTRIC FLUX AND GAUSS LAW

    CENGAGE PHYSICS|Exercise MCQ s|38 Videos

Similar Questions

Explore conceptually related problems

A resistance R_(1) of thermal coefficient of resistivity a is connected in parallel with resistance R_(2) having thermal coefficient of resistivity 3a .If the value of effective thermal coefficient of resistivity is (7 alpha)/(3) , then value of (R_(1))/(R_(2)) is

A wire of cross-section area A , length L_(1) , resistivity rho_(1) and temperature coefficient of resistivity alpha_(1) is connected in series to a second wire of length L_(2) , resistivity rho_(2) temperature coefficient of resistivity alpha_(2) and the same area A , so that wires carry same current. Total resistance R is independent of temperature for small temperature change if (Thermal expansion effect is negligible)

If a resistance R_(2) is connected in parallel with the resistance R in the circuit shown, then possible value of current through R and the possible value of R_(2) will be

If resistors of resistance R_(1) and R_(2) are connected in parallel,then resultant resistance is "

Two resistance are in the ratio 1:4. if these are connected in parallel, their total resistance becomes 20 ohm. Find the value of each resistance

Two resistance of identical shape but of different resistivity of values 3 and 6 are connected in parallel combination .The effective resistivity of the combination is

If 3 resistances of 3 ohm each are connected in parallel, what will be their total resistance?

Two wires are of same length and same area of cross-section. If first wire has resistivity rho_1 and temperature coefficient of resistance alpha_1 but second wire has resistivity rho_2 and temperature coefficient of resistance alpha_2 . Their series equivalent resistance is independent of small temperature changes. Then

Two resistors R1 and R2 are in series.Their coefficients are alpha1 and alpha2 .Find the effective value of alpha ?

A wire of resistance R is divided in 10 equal parts. These parts are connected in parallel, the equivalent resistance of such connection will be