Question
Physics Question on Thermodynamics
The dimensions of four wires if the same material are given below. The increase in length is maximum in the wire of :
A
Length 100 cm, Diameter 1 mm
B
Length 200 cm, Diameter 2 mm
C
Length 300 cm, Diameter 3mm
D
Length 50 cm, Diameter 0.5 mm
Answer
Length 50 cm, Diameter 0.5 mm
Explanation
Solution
The correct option is: (D) Length 50 cm, Diameter 0.5 mm.
Given: Y = Δl / Fl aΔl / Fl = Δl / Fl a = Δl / Δl a = 1
a. Δl / l₂ = 1 / 100 Δl = l₂ / 100 Δl = 100 / 100 Δl = 1
b. Δl / 4 = 1 / 200 Δl = 4 / 200 Δl = 1 / 50 Δl = 0.02
c. Δl / 9 = 1 / 300 Δl = 9 / 300 Δl = 3 / 100 Δl = 0.03
d. Δl / (1/2)² = 1 / 50 Δl / (1/4) = 1 / 50 Δl = 1 / 12.5 Δl = 0.08
The options can be summarized as: a. Δl = 1 b. Δl = 0.02 c. Δl = 0.03 d. Δl = 0.08