Geometrical Optics — Physics STD 11 Science — Question

A thermos flask containing tea is shaken vigorously considering tea as a system.

1. Has heat been added to tea?
2. Has work been done on it?
3. Has its internal energy changed?
4. Does its temperature rise?

Is it possible to have interference between the waves produced by two violins? Why?

A brick weighing 4.0kg is dropped into a 1.0m deep river from a height of 2.0m. Assuming that 80% of the gravitational potential energy is finally converted into thermal energy, find this thermal energy is calorie.

The mass of a body is measured by two persons is 10.2kg and 10.23kg. Which one is more accurate and why?

Do specific heat and latent heat have the same dimensions?

According to kinetic theory of gases, explain absolute zero.

Why birds are often seen to swell their feathers in winter?

Relate emissivity 'e', absorptivity ‘a' and reflectivity ‘r’.

What will be the effect on the angle of contact of a liquid if the temperature increases?

Give the magnitude and direction of the net force acting on.
A car moving with a constant velocity of 30km/h on a rough road.