Lead, ingested or inhaled is a health hazard. After the addition of lead to petrol has been banned, what still are the sources of lead poisoning?

1. Smelting units
2. Pens and pencils
3. Paints
4. Hair oils and cosmetics

Consider the following kinds of organisms :

1. Bacteria
2. Fungi
3. Flowering plants

Some species of which of the above kinds of organisms are employed as biopesticides?

Graphene is frequently in the news recently. What is its importance?

1. It is a two-dimensional material and has good electrical conductivity
2. It is one of the thinnest but strongest materials tested so far
3. It is entirely made of silicon and has high optical transparency
4. It can be used as ‘conducting electrodes’ required for touch screens, LCDs and organic LEDs

Consider the following statements - If there were no phenomenon of capillarity

1. It would be difficult to use a kerosene lamp
2. One would not be able to use a straw to consume a soft drink
3. The blotting paper would fail to function
4. The big trees that we see around would not have grown on the earth

Electrically charged particles from space travelling at speeds of several hundred km/sec can severely harm living beings if they reach the surface of the Earth. What prevents them from reaching the surface of the Earth?

What is the role of ultraviolet (UV) radiation in the water purification systems?

1. It inactivates /kills the harmful microorganisms in water.
2. It removes all the undesirable odours from the water.
3. It quickens the sedimentation of solid particles, removes turbidity and improves the clarity of the water.