Most balloons, tyres and footballs are made of rubber. This is because rubber is:
Naturally available
Cheap
An electrical insulator
Soft and flexible
Opaque objects:
Reflect most of the light falling on them
Transmit most of the light falling on them
Absorb most of the light falling on them
Are strong and hard
1 kg of iron occupies less space compared to 1 kg of sponge. Why ?
Iron has less density than sponge
Iron and sponge have equal densities
Iron has more density than sponge
None
Which of the following material is hard, opaque and shines when freshly cut ?
Rubber
Wood
Tin
Plastic
Clinical thermometers are made up of glass. The important characteristic(s) considered for this selection is/are:
It is a bad conductor of heat
It is transparent
Both A and B
It is strong
A needle and a knife belong to the same group because:
They are transparent
They are hard and magnetic
They float on water
They are poor conductors of heat
Of our total body weight, about two thirds is made up of water and it is important to have a regular intake of water. This is because
Water has lots of vitamins and proteins
Water can dissolve a lot of substances
Water conducts heat very fast and there by maintains the body temperature
Water is stored as energy in our body
A mirror is
Opaque
Transparent
Tanslucent
Which of the following is suitable to make rain coats?
Cotton
Silk
Door locks are made of metals because metals:
Have luster
Are opaque
Are good conductors of heat
Are hard and strong
