Physics
(i) Find the equivalent resistance between A and B.
(ii) State whether the resistivity of a wire changes with the change in the thickness of the wire.
Related Questions
(i) Heat supplied to a solid change it into liquid. What is this change in phase called?
(ii) During the phase change does the average kinetic energy of the molecules of the substance increase?
(iii) What is the energy absorbed during the phase change called?
An electric iron is rated 220V, 2 kW.
(i) If the iron is used for 2h daily, find the cost of running it for one week if it costs ₹4.25 per kWh.
(ii) Why is the fuse absolutely necessary in a power circuit?
(i) A fuse is rated 8A. Can it be used with an electrical appliance rated 5 KW, 200 V? Give a reason.
(ii) Name two safety devices which are connected to the live wire of a household electric circuit.
A person is standing at the sea shore. An observer on the ship which is anchored in between a vertical cliff and the person on the shore fires a gun. The person on the shore hears two sounds, 2 seconds and 3 seconds after seeing the smoke of the fired gun. If the speed of sound in the air is 320 ms-1 then calculate:
(i) the distance between the observer on the ship and the person on the shore.
(ii) the distance between the cliff and the observer on the ship.
