Thermodynamics — Physics STD 11 Science — Question

In the upper wire is made of steel and the lower of copper. The wires have equal cross-section. Find the ratio of the longitudinal strains developed in the two wires.

A man with a wrist watch on his hand falls from the top of a tower. Does the watch give correct time during the free fall?

A 100pF capacitor is charged to a potential difference of 24V. It is connected to an uncharged capacitor of capacitance 20pF. What will be the new potential difference across the 100pF capacitor?

Find the flux of the electric field through a spherical surface of radius R due to a charge of 10^-7C at the centre and another equal charge at a point 2R away from the centre.

If suddenly the gravitational force of attraction between the earth and a satellite revolving around it becomes zero, what will happen to the satellite?

Define the terms elastic collision and inelastic collision. What is the difference between inelastic collision and a completely inelastic collision?

Consider a small cube of volume 1mm³ at the centre of a circular loop of radius 10cm carrying a current of 4A. Find the magnetic energy stored inside the cube.

When pressure increases by 1%, what is the percentage decrease in the volume of a gas, if Boyle's law is obeyed?

Just as precise measurements are necessary in science, it is equally important to be able to make rough estimates of quantities using rudimentary ideas and common observations. Think of ways by which you can estimate the following (where an estimate is difficult to obtain, try to get an upper bound on the quantity):
The number of strands of hair on your head.