Which of the following statements are correct in reference to the role of A (shown in the given diagram) during a breathing cycle in human beings?

(i) It helps to decrease the residual volume of the air in lungs.

(ii) It flattens as we inhale.

(iii) It gets raised as we inhale.

(iv) It helps the chest cavity to become larger.

1. (ii) and (iv)
2. (iii) and (iv)
3. (i) and (ii)
4. (i), (ii) and (iv)

Which one of the following conditions is true for the state of stomata of a green leaf shown in given diagram?

1. Large amount of water flows into the guard cells.
2. Gaseous exchange is occurring in large amount.
3. Large amount of water flows out from the guard cells.
4. Large amount of sugar collects in the guard cells.

A student wants to obtain a magnified image of an object AB as on a screen. Which one of the following arrangements shows the correct position of AB for him/her to be successful?

1.

2.

3.

4.

The following diagram shows the use of an optical device to perform an experiment of light. As per the arrangement shown, the optical device is likely to be a;

1. Concave mirror
2. Concave lens
3. Convex mirror
4. Convex lens