The coefficient of cubical expansion of mercury is 0.00018 and that of brass 0.00006 per deg C. If a barometer having a brass-scale were to read 74.5 cm at `30^@C`, find the true barometric height at `0^@C`. The scale is supposed to be correct at `15^@C`.

A brass rod of length 50 cm and diameter 3.00 mm is joined to a steel rod of the same length and diameter. What is the change in length of the combined rod at 250^@C , if the original lengths are at 40.0^@C ? Is there a 'thermal stress' developed at the junction? The ends of the rod are free to expand coefficent of linear expansion of brass = 2.0 xx 10^-5 ^@C^-1 , steel = 1.2 xx 10^-5 ^@C^-1 ).

Answer the following There were two fixed points in the original celsius scale as mentioned above which were assigned the number 0^@C and 100^@C respectively. On the absolute scale, one of the fixed points is the triple point of water which on the kelvin absolute scale is assigned the number 273.16 K. What is the other fixed point on this (kelvin ) scale?

A brass and an iron rod are each of one metre long at 0^@C . Find the difference in their lengths at 100^@C . Coefficient of linear expansion of brass is 0.000019 and of iron = 0.000012.

A cylinder of diameter exactly 1 cm at 30^@C is to be slided into a hole in a steel plate. The hole has a diameter of 0.99970 cm at 30^@C . To what temperature must the plate be heated? For steel alpha = 1.1 xx 10^-5 ^@C^-1

A steel tape 1 metre long is correctly calibrated for temperature of 27.0^@C . The length of a steel rod measured by this tape is found to be 63.0 cm on a h ot day when the temperature is 45^@C . What is the actual length of the steel rod on that day? What is the length of the same steel rod on a day when the temperature is 27.0^@C ? Coefficient of linear expansion of steel = 1.20 xx 10^-5 C^-1 .

A 5.0 cm long needle is placed vertically at a distance 20 cm in front of a double convex lens made of a material of refractive index 1.5 having radii of curvature as 20 cm and 30 cm .Find the height of image formed.

A 2.0 cm long needle is placed vertically at a distance 48 cm in front of a double convex lens made of a material of refractive index 1.5 having radii of curvature as 20 cm and 30 cm. Find the height of image formed.