Ask Question
7 April, 08:24

The filament of a certain lamp has a resistance that increases linearly with temperature. When a constant voltage is switched on, the initial current decreases until the filament reaches its steady-state temperature. The temperature coefficient of resistivity of the filament is 43 times 10^-3 K^-1. The final current through the filament is one - eighth the initial current. What is the change in temperature of the filament?

a. 30100 K

b. 378 K

c. 1627 K

d. 814 K

e. 1162 K

+2
Answers (1)
  1. 7 April, 10:34
    0
    162.8 K

    Explanation:

    initial current = io

    final current, i = io/8

    Let the potential difference is V.

    coefficient of resistivity, α = 43 x 10^-3 / K

    Let the resistance is R and the final resistance is Ro.

    The resistance varies with temperature

    R = Ro (1 + α ΔT)

    V/i = V/io (1 + α ΔT)

    8 = 1 + 43 x 10^-3 x ΔT

    7 = 43 x 10^-3 x ΔT

    ΔT = 162.8 K

    Thus, the rise in temperature is 162.8 K.
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “The filament of a certain lamp has a resistance that increases linearly with temperature. When a constant voltage is switched on, the ...” in 📘 Physics if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers