Gravitation — Science STD 9 — Question

Which one of the following is most likely not a case of uniform circular motion?

When speed is stated along with its direction, it is called as:

When a rubber balloon held between the hands is pressed, its shape changes. This happens because:

Which one of the following statements about power stations is not true?

1. Hydroelectric power stations use water to drive turbines.
2. In a power station, turbines drive generators.
3. Electricity from thermal power stations differs from that produced in hydroelectric power stations.
4. In hydroelectric power stations and thermal power stations, alternators produce electricity.

The mass number of two atoms X and Y is the same (40 each) but their atomic numbers are different (being 20 and 18 respectively). X and Y are examples of:

A body cannot have a:

With increase in surface area,

A particle P has 18 electrons, 20 neutrons and 19 protons. This particle must be:

White gold used in jewellery contains two elements, gold and palladium. A jeweller has two different samples that are both identical in appearance and have a uniform composition throughout. What can be said about the samples?