Some effects of thermal expansion in solids

(1)  BIMETALLIC STRIP :- If two strips of different materials placed one over another and rigidly joint is called bimetallic strip.


:- If a bimetallic strip is heated then it bends such that the strip  of  material having high value of coefficient of linear thermal expansion will be on convex side.

α of brass rod > α of steel rod

(2)  Time period of pendulum

     


Thred length of pendulum = l

Acceleration due to gravity = g


T   =   2π    (l/g)

Log T = Log (2π) + Log(l) - Log (g)


                           Take both side Differentiation




(1) A wall clock that gives the correct time at 25°C  If that wall clock is kept at 55°C then how much time will it gain or lose in one day ? (coefficient of linear thermal expansion of the pendulum is 1.2 ×10⁻⁵/°C)

(2) A second's pendulum of wall clock has a steel  wire . the clock is placed at 20°C , How much time does the clock loss or gain  in one month when the temperature is increased  to 40°C ?  ( α = 1.2 × 10⁻⁵/°C )













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