Question

Match List-I with List-II.

List-I	List-II
(Metal)	(Application)
(a) Cs	(I) High temperature thermometer
(b) Ga	(II) Water repellent sprays
(c) B	(III) Photoelectric cells
(d) Si	(IV) Bullet proof vest

Choose the most appropriate answer from the options given below:

विकल्प

• (a) - (III), (b) - (I), (c) - (IV), (d) - (II)

• (a) - (IV), (b) - (III), (c) - (II), (d) - (I)

• (a) - (II), (b) - (III), (c) - (IV), (d) - (I)

• (a) - (I), (b) - (IV), (c) - (II), (d) - (III)

Answer 1

(a) - (III), (b) - (I), (c) - (IV), (d) - (II)

Explanation:

List-I	List-II
(Metal)	(Application)
(a) Cs	(III) Photoelectric cells
(b) Ga	(I) High temperature thermometer
(c) B	(IV) Bullet proof vest
(d) Si	(II) Water repellent sprays

Caesium is used in the design of photoelectric cells. Bullet-proof vests are made with boron fibres. Silicones are water repellent in nature because they are surrounded by non-polar alkyl groups. Gallium is used in high-temperature thermometers because it is less toxic and has a very high boiling point.