Different methods of extinguishing a fire involve the following :
I. Removing the combustible substance.
II. Cooling the substance to a temperature below its ignition temperature.
III. Cutting off the supply of air.
Which of the following statements is correct?
A Method I is suitable in case of a building on fire.
B Method II involves water which works when wood or paper are on fire.
C Method III involves carbon dioxide gas which is lighter than oxygen and forms a blanket around the air.
D All of these
whats wrong with B
Select the incorrect statement.
(a) The weaver bird uses its beak like a needle to sew leaves and other materials to make a nest.
(b) The penguin collects a few pebbles and stones to make a nest.
(c) Eagle and vulture simply put a few sticks together to make a shallow nest.
(d) The woodpecker pecks a tree trunk with its beak to make a hole for nest.
Refer the given conversation about simple machines. Identify the INCORRECT option regarding P, Q and R.
AQ can be used to hold things.
BP can be axe or knife.
CR can be a ramp in hospitals.
DQ helps to move heavy objects.
how P can be axe or knife because it should have 2 inclined surface joined together. P has to be some type of scissor. There are 2 answers for this question B n D
Which one of the following set-ups does not show that air occupies space?
The diagram in this question is not very clear. I don't understand option A. And I don't understand why the answer is D
Which of the following does not have bones and moves with the help of contractions and expansions of the body?