(English Medium) ICSE Class 9 - CISCE Question Bank Solutions

Differentiate between:
Flow of electron and flow of conventional current.

Write the formula for speed of sound in a gas using Laplace correction.

Why does the flash of lighting reach earlier than the sound of thunder?

What are land and sea breezes? Explain with the help of a labeled diagram.

In cold countries, the water pipes are covered with poor conductors. Why?

Why does a thick glass tumbler crack when very hot water is poured in it?

The following diagrams illustrate three situations involving thermometers which are labeled A, Band C. In each situation the thermometers indicate different readings.

(i) What do you expect the approximate reading of the thermometer B and C would be? Give a reason for your answer.
(ii) How would the readings of A and B help you in calibrating a thermometer?

The following figure shows a metal cylinder, containing boiling water. One half side A is polished and another half, B is painted black. Two thin metal sheets X and Y are painted black and have one rubber stopper fixed with wax on each sheet. These sheets are equidistant from the boiling water (container A, B) as shown in the diagram. What would you expect to happen after a few minutes? Give a reason for your answer.

Exercise

Study the following diagrams and write down your observations.

What is the criterion of choosing the two metals for a bimetal strip?

Give reasons for the following:

Even when the water in the lakes is frozen, fish can survive.

What will be the approximate temperature of water in the lake shown in the following diagram?

(i) At X, and
(ii) At Y?