A man travels 800 km in partly by rail and partly by steamer. He spends 7 hours more time on steamer. If the velocity of the steamer is 20 km/hr and the velocity of rail is 55 km/hr, how much distance does he cover by steamer?
What is the resistance (in ohm) of an electrical component if a current of 0.5 A passes through it on application of 20 V of potential difference across it?