Answer: A) +6 Explanation: In H2SO4, Hydrogen has a charge of +2, with each hydrogen has +1. Oxygen has  a charge of -8, with each oxugen has -2. Total charge = (2 - 8) = -6 Therefore, the Oxidation number of Sulphur S is '+6' because to make the compound stable.

Answer: A) Chandigarh Explanation:

Answer: A) HIV Explanation: ELISA - Enzyme-Linked Immuno Sorbent Assay.   An ELISA test may be used to diagnose: HIV, which causes AIDS.   An ELISA also called EIA, is a test that detects and measures antibodies in your blood. Antibodies are proteins that your body produces in response to harmful substances called antigens.

Answer: A) Decrease in the thickness of ozone layer in Stratosphere Explanation:

Answer: C) 34 cm Explanation: Let the side of the square be 's' cm   length of rectangle = (s+5) cm   breadth of rectangle = (s-3)cm   (s+5) (s-3) =    s2 - 5s - 3s - 15 = s2    2s = 15   Perimeter of rectangle = 2(L+B) = 2(s+5 + s–3) = 2(2s + 2)   = 2(15 + 2) = 34 cm

I am History.   Yes, history refers to all the past, but we can create history in the presentand it cannot be polluted in the future.

From given data, (C.P. of 17 balls) - (S.P. of 17 balls) = (C.P. of 5 balls) C.P. of 12 balls = S.P. of 17 balls = Rs.720. Hence, C.P. of 1 ball = Rs.720/12 = Rs. 60.

Answer: B) 29.25 hrs Explanation: Let the leak will empty the tank in x hrs  Then, 1/9 - 1/x = 1/13 x = 29.25 hrs