Sound — Science STD 9 — Question

The chemical which can be used to separate a mixture of carbon powder and sulphur powder successfully is:

Find the correct statement:

P.E of a spring increases when it is in the state of:

Pure copper sulphate can be obtained form an impure sample by the process of:

In water, the proportion of oxygen and hydrogen by mass is:

1. 1 : 4
2. 1 : 8
3. 4 : 1
4. 8 : 1

When the amplitude is small, the sound produced is ......:

Lysosomes were discovered by:

The force of gravitation exists:

Coolers are more effective in areas with ___________?

Run-off from fertilizer-rich crop-fields causes:

1. Turbidity of water bodies.
2. Precipitation of toxicants.
3. Eutrophication of water bodies.
4. Thermal pollution of water bodies.