Current Electricity Charging Discharging Of Capacitors Question 530
Question: 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
[MP PET 2001]
Options:
A) 3 min 20 sec
B) 5 min
C) 7 min 30 sec
D) 2 min 30 sec
Show Answer
Answer:
Correct Answer: A
Solution:
In parallel $ \frac{1}{t _{p}}=\frac{1}{t _{1}}+\frac{1}{t _{2}} $
Therefore $ t _{p}=\frac{t _{1}t _{2}}{t _{1}+t _{2}} $
$ =\frac{5\times 10}{5+10}=\frac{50}{15}=3.33,\min $
$ =3,min.,20,sec $
BETA
