An electric kettle has two coils of same power . When one coil is switched on , it takes `15 min` to boil water , and when the second coil is switched on , it takes `30 min`. How long will it take to boil water when both the coils are used in `i`. Series and `ii`. parallel?

An electric kettle has two coils. When one coil is switched an it takes 5 minutes to boil water and when second coil is switched on it takes 10 minutes .How long will it take to boil water, when both the coil are used in series ?

An electric kettle has two coils. When one of these is switched on, the water in the kettle boils in 15 minutes. When the other is switched on, the water boils in 30 minutes. In how many minutes will water boil if the coils are connected in series and switched on?

An electric tea kettle has two heating coils. When one of the coils is switched on , boiling begins in 6 min . When the other coil is switched on , boiling begins in 8 min . In what time will the boiling begin if both coils are switched on simultaneously (i) in series and (ii) in parallel.

An electric tea kettle has two heating coils. When one of the coils is switched on , boiling begins in 6 min . When the other coil is switched on , boiling begins in 8 min . In what time will the boiling begin if both coils are switched on simultaneously (i) in series and (ii) in parallel.

An electric heater has heating coils A and B , when coil A is switched on, the water boils in 10 minuts, and when coil B is switched on the water boils in 20 minuts. Calculate the time taken by water, to boil if the coils conneted in (a) Series and (b) Parallel all switched on.

An electric kettle has two heating coils. When one of them is switched on water in it boils in 6 minutes and when other is switched on water boils in 4 minutes. In what time will the water boil if both coil are switched on simultaneously

An electric tea kettle has two heating coils. When one of the coils is switched on, boiling begins in 6 min. When the other coil is switched on, the boiling begins in 8 min. In what time, will the boiling begin if both coils are switched on simultaneously (i) in series and (ii) in parallel.