A wire of length 80 cm has a frequency of 256 Hz. Calculate the length of a similar wire under similar tension, which will have frequency 1024 Hz.

A certain sound has a frequency of 256 hertz and a wavelength of 1.3 m.
1. Calculate the speed with which this sound travels
2. What difference would be felt by a listener between the above sound and another sound travelling at the same speed, but of wavelength 2.6 m?

43.

Name the colour code of the wire which is connected to the metallic body of an appliance.

Draw the diagram of a dual control switch when the appliance is switched ‘ON’.

 Which particles are responsible for current in conductors?

To which wire of a cable in a power circuit should the metal case of geyser be connected.

To which wire should the fuse be connected?

Answer the following questions based on a hot cathode ray tube.
(i) Name the charged particles
(ii) State the approximate voltage used to heat the filament
(iii) What will happen to the beam when it passes through the electric field?

State three factors on which the rate of emission of electrons from a metal surface depends?

What are free electrons?