You heat a 541cm^3 sample of a substance from 133°c to 273°c and find that its volume increases by 2.25 cm^3. calculate the coefficient of volume expansion of this substance.

Explanation:

As we know by the theory of expansion the change in the volume of the object is directly proportional to change in temperature and initial volume.

So here we can say

here

= coefficient of volume expansion

so we have

now plug in all values

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it