A clock with a metal pendulum beating seconds keeps correct time at 0∘C. If it loses 12.5 s a day at 25∘C, the coefficient of linear expansion of metal of pendulum is
The correct option is D. .
We know that,
Loss of time due to heating a pendulum is given as ΔT = 12αΔθT
△T = change in time
α = coefficient of linear expansion of metal of pendulum
△θ = change in temperature
T = total time
⇒ 12.5 = 12 × α × (25−0)∘C × 86400
(Since 24 hr = 86400 seconds)
⇒ α = 186400 /∘C.