4491: Which one of the following stars is nearest to the earth ?

(a) Polaris
(b) Alpha Centauri
(c) Sun
(d) Sirius
4492: Recently, linking of which of the following rivers was undertaken?

(a) Cauvery and Tungabhadra
(b) Godavari and Krishna
(c) Mahanadi and Sone
(d) Narmada and Tapti
4493: Four metal rods of lengths 78 cm, 104 cm, 117 cm and 169 cm are to be cut into parts of equal length. Each part must be as long as possible. What is the maximum number of pieces that can be cut?

(A) 36
(B) 43
(C) 27
(D) 11

4494: In a dry cell (battery), which of the following are used as electrolytes?

(a) Ammonium chloride and Zinc chloride

(b) Sodium chloride and Calcium chloride

(c) Magnesium chloride and Zinc chloride

(d) Ammonium chloride and Calcium chloride
4495: Assertion (A):

The thickness of the atmosphere is maximum over the Equator.

Reason (R):

High insolation and strong convection currents occur over the Equator.

(a) Both A and R are individually true and R is the correct explanation of A
(b) Both A and R are individually true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true