A wire of a certain material is stretched slowly by ten percent. Its new resistance

A wire of a certain material is stretched slowly by ten percent. Its new resistance and specific resistance become respectively

Options

(a) both remain the same
(b) 1.1 times, 1.1 times
(c) 1.2 times, 1.1 times
(d) 1.21 times, same

Correct Answer:

1.21 times, same

Explanation:

Δl / l = 0.1 , Therefore, l = 1.1 but the area also decreases by 0.1.

mass = ρlA = Vρ. In l + In A = 1n mass.

.·. Δl / l = ΔA / A = 0 ⇒ Δl / l = -ΔA / A

Length increases by 0.1, resistance increases, area decreases by 0.1, then also resistance will increase. Total increase in resistance is approximately 1.2 times, due to increase in length and decrease in area. But specific resistance does not change.

admin:

Related Questions

  1. A proton of mass m and charge q is moving in a plane with kinetic energy E. If there exists
  2. If the highest modulating frequency of the wave is 5 kHz, the number
  3. The voltage of an a.c.supply varies with time (t) as V=120 sin 100 πt the maximum voltage
  4. The refracting angle of a prism is A and refractive index of the material of the prism
  5. A thin wire of length L and mass M is bent to form a semicircle.