Let S = {1, 2, 3, .., 40} and let A be a subset of S such that no two elements in A have their sum divisible by 5. What is the maximum number of elements possible in A ?
option
(A) 10
(B) 13
(C) 17
(D) 20
An aqueous buffer is prepared by adding 100 ml of 0.1 mol l-1 acetic acid to 50 ml of 0.2 mol l-1 of sodium acetate. If pKa of acetic acid is 4.76, the pH of the buffer is
option
(A) 4.26
(B) 5.76
(C) 3.76
(D) 4.76
In evolutionary terms, an Indian school boys is more closely related to
(A) an Indian frog (B) an American snake
(C) a Chinese horse (D) an African shark
A circle is drawn in a sector of a larger circle of radius r, as shown in the adjacent figure. The smaller circle is
tangent to the two bounding radii and the arc of the sector. The radius of the small circle is
On a horizontal frictionless frozen lake, a girl (36 kg) and a box (9 kg) are connected to each other by means of a rope. Initially they are 20 m apart. The girl exerts a horizontal force on the box, pulling it towards her. How far has the girl traveled when she meets the box >
(A) 10 m
(B) Since there is no friction, the girl will not move
(C) 16 m
(D) 4m
A girl brings a positively charged rod near a thin neutral stream of water from a tap. She observes that the water stream bends towards her. Instead, if she were to bring a negatively charged rod near to the steam, it will
option
(A) Bend in the same direction
(B) Bend in the opposite direction
(C) Not bend at all
(D) Bend in the opposite direction above and below and rod