Question
Which of the following acid proves to be useful for the
purification of gold and silver?Solution
Nitric acid is used for purification of various precious metals, including gold, silver, and platinum. In metallurgy, it is used in combination with alcohol for etching designs on metals like brass, copper, bronze, etc.
- Train ‘X’ is 360 metres long and takes 18 seconds to cross a pole. Speed of train ‘Y’ is 22 m/sec. If both trains cross each other in 16 seconds wh...
Train A when travelling with a speed of 144 km/h crosses a pole in 6 seconds. Find the time taken by the train A to cross another train B of length 25% ...
Train A, moving at 90 km/h, crosses a pole in 8 seconds. Find the time it takes to cross another train of equal length, coming from the opposite directi...
Two trains running on parallel track with lengths 140 m and 40 m respectively. When travelling in opposite directions they are observed to pass each oth...
- Train 'A' having a speed of 25 m/s can cross a man in 6 seconds. The length of train 'B' is 30 metres more than the length of 'A'. If the speed of 'B' is 3...
Length of train 'X' is (35n - 30) metres, which is 200 metres more than that of train 'Y'. Time taken by 'X' and 'Y' to cross a pole is 20 seconds and 1...
Train ‘A’ running with a speed of 108 km/hr crosses a vertical pole in 13 seconds. Find the approx. time taken by the train ‘A’ ...
A 360 m long train crosses a platform twice its length in 2 min. Find the speed of the train.
A train takes to cross a man standing on a platform and a 360m long bridge 12 sec and 30 sec respectively. How long will it take to cross a 220m long pl...
A train of length 150 m passes a platform of length 350 m in 25 s.
Find: (i) speed of the train in km/h, (ii) time to pass a man standing still.
