A clock with an iron pendulum keeps correct time at `20^(@)C`. How much time will it lose or gain in a day if the temperature changes to `40^(@)C`. Thermal coefficient of liner expansion `alpha = 0.000012 per^(@)C`.

Answer

A, C

Explanation

`Delta T = (1)/(2) T alpha Delta theta`
rArr `Delta t = (Delta T)/(T^(1) t`
But `T' ~~ T`
`:. Delta t = (1)/(2) alpha Delta theta (t)`
`= (1)/(2) xx 0.000012 xx 20 xx 24 xx 3600`
` = 10.37 s`
At higher temperture, length of pendulum clock will be more. So, time period will be more and it will lose the time.