A student records the initial length l, change in temperature `DeltaT` and change in length `Deltal` of a rod as follows: If the first observation is correct, what can you say about observations 2, 3 and 4?

If M is the mid point of XY ,what can you say about the lengths MX and XY?

Answer the following questions: A magnetic field that varies in magnitude from point to point but has a constant direction (east to west) is set up in a chamber. A charged particle enters the chamber and travels undeflected along a straight path with constant speed. What can you say about the initial velocity of the particle?

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 ).

We would like to prepare a scale whose length does not change with temperature. It is proposed to prepare a unit scale of this type whose length remains, say 10 cm. We can use a bimetallic strip made of brass and iron each of different length whose length (both components) would change in such a way that difference between their lengths remains constant. If alpa_(iron = 1.2 xx 10^-5 //K and alpha_(brass = 1.8 xx 10^-5//K , what should we take as length of each strip?

An equilateral triangle ABC is formed by two Cu rods AB and BC and one Al rod. It is heated in such a way taht temperature of each rod increases by DeltaT . Find change in the angle ABC. [Coeff. of linear expansion for Cu is a_1 , Coeff. of linear expansion for Al is a_2l