Answer it fast... Board examination class 10 cbse...
Answers
Explanation:
1. (R3R4/R3+R4)+R1+R2
2.Joule's law of heating states that when a current 'i ' passes through a conductor of resistance 'r' for time 't' then the heat developed in the conductor is equal to the product of the square of the current, the resistance and time.
3.If the current is much more than 4.5 amperes, the electric iron can get damaged. ... Thus, We must use the 5 A fuse. It will protect the iron from voltage and current overloading. In your calculations, you must have taken an improper value of Power, something like 100 watts, which gave you your answer.
4.When appliances are connected in series, total resistance of circuit increases. This decreases the current and hence the power through each appliance. In order to avoid this loss of current, and hence of power, through bulb and heater, they are connected in parallel.