Current Electricity — Physics STD 10 — Question

A fixed pulley is driven by a 100 kg mass falling at a rate of 8.0 m in 4.0 s. It lifts a load of 75.0 kgf.
Calculate the efficiency of the pulley.

The input and output voltages of a transformer are 220 V and 44V respectively. Find the current in input circuit if the output current is 2 A.

Obtain an expression for the potential energy of a body of mass m at a height h above the ground.

What do you understand by free vibrations of a body? Draw a displacement-time graph to represent them. Given one example.

The diagram below shows a rod lifting a stone.
(a) Mark position of fulcrum F and draw arrows to show the directions of load L and effort E.
(b) What class of lever is the rod?
(c) Give one more example of the same class of lever stated in part (b).

A vessel of negligible heat*capacity contains 40g of ice in it at 0°C, 8g of steam at 100°C is passed into the ice to melt it. Find the final temperature of the contents of the vessel.
(Specific latent heat of vaporization of steam = 2268 J/g, specific latent heat of fusion of ice = 336 J/f and specific heat capacity of water = 4.2 J/g°C)

A boy of mass 30 kg is fitting at a distance of 2 m from the middle of a see-saw. Where should a boy of mass 40 kg sit so as to balance the see-saw?

State three ways to minimize the global warming.