Which of the following steps can be followed for making the apparatus air tight?
(i) placing the plants on glass plate
(ii) using a suction pump.
(iii) applying aseline to seal the bottom of jar.
(iv) creating vacuum
(A) i and ii
(B) ii. and iii
(C) i. and iii
(D) ii. and iv
Answer -
Let’s check each option
-
For (i)
- If we
place plants
on glass plate, it will make sure that there is no gap between the jar and the bottom. So,
we can use this step.
-
For (ii)
- If we use a
suction pump,
it will remove all the air inside the jar. So, this step
does not
make the apparatus air tight, it just removes the air
-
For (iii)
- Vaseline
will
seal moisture
and help the jar set at the bottom. So,
we can use this step.
- For (iv) - If we create vaccum, it will remove all the air inside the jar. So, this step does not make the apparatus air tight, it just removes the air
Thus,
(i) and (iii) are correct
So, the correct answer is (c)
