Answer: A) Chemical Explanation: In rusting the Iron ore make a chemical reaction with the oxygen in the presence of water and environmental or atmospheric moisture to produce an Iron oxide. Iron oxide is otherwise called as rust. The rusting of iron is a chemical change because it is two substances reacting together to make a new substance.

Answer: A) the mass of the liquid displaced Explanation: Buoyancy or Upthrust, is an upward force exerted by a fluid that opposes the weight of an immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid.

The formula to find the volume is given by just multiplying Length, Breadth and Height of that object.   Thus, V = L x B X H   Volume Formulae :    1. Volume of Cube of side 's' = s x s x s = s3  cubic units.    2. Volume of Cylinder = πR2h cubic units.   [Where R is Radius and h is height]

Answer: B) GSLV-Mark-III Explanation: India’s first indigenously designed and developed high thrust cryogenic rocket engine generating a nominal thrust of 19 tonnes was successfully endurance hot tested for a duration of 800 seconds on July 16, 2015 at ISRO Propulsion Complex, Mahendragiri.   The engine will be used for powering the Cryogenic stage (C25), the upper stage of the next generation GSLV Mark-III launch vehicle of ISRO, capable of launching four tonne class satellites.   This cryogenic engine of C25 Stage operates on Gas Generator Cycle using extremely low temperature propellants – Liquid Hydrogen (LH2) at 20 Kelvin (-253 deg C) and Liquid Oxygen (LOX) at 80K (-193 deg C).

Answer: A) Iran Explanation:

Answer: D) 16.38 Explanation: Given, Manideep purchases 30kg of barley at the rate of 11.50/kg nad 20kg at the rate of 14.25/kg. Total cost of the mixture of barley = (30 x 11.50) + (20 x 14.25) => Total cost of the mixture = Rs. 630 Total kgs of the mixture = 30 + 20 = 50kg Cost of mixture/kg = 630/50 = 12.6/kg To make 30% of profit => Selling price for manideep = 12.6 + 30% x 12.6 => Selling price for manideep = 12.6 + 3.78 = 16.38/kg.

Answer: C) Parineeti Chopra Explanation: