Echoes and Vibrations of Sound — Physics STD 10 — Question

Name a machine to change the direction of force ?

Bends in a rubber pipe reduce the flow of water through it. How would the bands in a wire affect its electric resistance?

A straight wire is held vertical and current is passed in it in the upward direction. A compass needle is kept near the wire in north of it. How is the needle deflected? What is the change in the deflection of the needle if the current in wire is reversed?

What is musical sound? Give an example.

The following diagram shows a spiral coil wound on a hollow carboard tube AB. A magnetic compass is placed close to it. Current it switched on by closing the key. (a) What will be the polarity at the ends A and B? (b) How will the compass needle be affected? Give reason.

A student puts his pencil into an empty trough and observes the pencil from the position as indicated in Fig. 4.37

(i) What change will be observed in the appearance of the pencil when water is poured into the trough?
(ii) Name the phenomenon which accounts for the above stated observation.
(iii) complete the diagram showing how the student’s eye sees the pencil through water.

Give two difference between an ohmic and non-ohmic resistor.

What do you understand by the term "scattering of light"? Which colour of white light is scattered the least and why?

(a) Name and define the standard commercial unit of electric energy.
(b) What is the function of the following in the household wiring?
(i) main switch, (ii) three pin plug