i) Sometimes when a vehicle is driven at a particular speed, a rattling sound is heard. Explain briefly, why this happens and give the name of the phenomenon taking place.
ii) Suggest one way by which the rattling sound could be stopped.i) Phenomenon is resonance: When the frequency of engine becomes equal to the body of vehicle, some parts of the vehicle start vibrating violently. Due to resonance rattling sound is heard.
ii) Rattling sound can be stopped by changing the speed of vehicle.
i) How does the heat produced in a wire or a conductor depend upon the:
1. current passing through the conductor.
2. Resistance of the conductor?
ii) Draw a simple sketch of the step-down transformer. Label the different parts I the diagram.
A piece of ice of mass 40 g is dropped into 200 g of water at 50 degree Celsius.
Calculate the final temperature of water after all the ice has been melted.i) The given diagram shows an electron gun of a hot cathode ray tube,
1. Name the parts X and Y.
2. A 6 V d.c. source and a 1000 V d. C. Source are available. Dhow how these sources should be connected to the terminals of X and Y soa s to obtain a focused beam of fast moving electrons.
ii) Give one use of a cathode ray tube?