An electric kettle has two coils. When one of these is switched on, the water in the kettle boils in 6 minutes. When the other coil is switched on, the water boils in 3 minutes. If the two coils are connected in series, find the time taken to boil the water in the kettle.
Text Solution
Verified by Experts
Heat produced, `H = V^(2)t//JR or R prop t` so `R_(1) prop 6` and `R_(2) prop 3`, therefore, `R_(1)//R_(2) =6//3 =2` or `R_(1) = 2 R_(2)` When coils are connected in series, then net resistance, `R' = R_(1) + R_(2) = 3 R_(2)` so `(R')/R_(2) = (t')/(3)` or `t'= (3R')/(R_(2)) = (3xx3R_(2))/R_(2) = 9` minutes
Topper's Solved these Questions
CURRENT ELECTRICITY
PRADEEP|Exercise Conceptual Problems|3 Videos
CURRENT ELECTRICITY
PRADEEP|Exercise Very short Q/A|7 Videos
COMMUNICATION SYSTEMS
PRADEEP|Exercise MODEL TEST PAPER-2|9 Videos
DUAL NATURE OF RADIATION AND MATTER
PRADEEP|Exercise Exercise|191 Videos
Similar Questions
Explore conceptually related problems
An electric kettle has tow heating coils. When one of the coils connected to an AC source, the water in the kettle boils in 10 min. when the other coil is used the water boils in 40 min. if both the coils are connected in parallel, the time taken by the same quantity of water of boil will be
An electric kettle has two heating coils. when one coil is used, water in the kettle boils in 5 minutes, while when second coil is used, same water boils in 10 minutes. If the two coils, connected in parallel are used simultaneously.the same water will boil in time
An electric kettle has two heating coils. When one coil is used, water in the kettle boils in 5 minutes, while when second coil is used, same water boils in 10 minutes. If the two coils, connected in parallel are used simultaneously, the same water will boil in time
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 kettle has two windings. When one of the n is switched on the kettle begins to boil in t_(1) minutes and when the other is switched on it begins to boil in t_(2) minutes. In what time will the kettle begin to boil if both windings are switched on simultaneously in series and a 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 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 kettie has two coils. When one coil is switched on it takes 15 minutes and the other takes 30 minutes to boil certain mass of water. The ratio of times taken by them, when connected in series and in parallel to boil the same mass of water is
PRADEEP-CURRENT ELECTRICITY-Problems for Practice (B)
