1771: Assertion (A) :
A man standing on a completely friction-less surface can propel himself by whistling.
Reason (R) :
If no external force acts on a system, its momentum cannot change.
(a) Both A and R are true, and R is the correct explanation of A
(b) Both A and R are true, but R is not a correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true
1772: In a family there are husband wife, two sons and two daughters. All the ladies were invited to a dinner. Both sons went out to play. Husband did not return from office. Who was at home ?
(a) Only wife was at home
(b) All ladies were at home
(c) Only sons were at home
(d) No body was at home
1773: A walks around a circular field at the rate of one round per hour while B runs around it at the rate of six rounds per hour. They start in the same direction from the same point at 7.30 a.m. They shall first cross each other at
(a) 8.30 a.m.
(b) 8.10 a.m.
(c) 7.48 a.m.
(d) 7.42 a.m.
1774: In which one of the following areas in the given map was there a recent discovery of copper deposits by the Atomic Minerals Division of Department of Atomic Energy ?
(a) 1
(b) 2
(c) 3
(d) 4
1775: The following persons came to India at one time or another :
I. Fa-Hien
II. I-Tsing
III. Megasthenese
IV. Hieun-Tsang
The correct chronological sequence of their visits is :
(a) III, I, II, IV
(b) III, I, IV, II
(c) I, III, II, IV
(d) I, III, IV, II