An electric kettle has two heating coils. When one of the coil is connected to an alternating current source the water in the kettle boils in 10 minutes. When the other coil is used, the same quantity of water takes 15 minutes in boil. How long will it take for the same quantity of water to boil, if the two coils are connected in parallel ? 

This question was previously asked in
HTET TGT Science 2021 Official Paper
View all HTET Papers >
  1. 6 minute 
  2. 12 minute
  3. 18 minute 
  4. 24 minute 

Answer (Detailed Solution Below)

Option 1 : 6 minute 
Free
HTET PGT Official Computer Science Paper - 2019
60 Qs. 60 Marks 60 Mins

Detailed Solution

Download Solution PDF

Concept:

We know that for parallel connection, the equivalent resistance is give n by:

Power (P) = VI = V2/R = I2R

Also

Heating Effect (Q) = Power × Time

Q = VIt = V2t/R = I2Rt

Since the coils are connected in parallel, therefore Voltage will be same, so we will use the following relation.

Q = V2t/R

Similarly

Calculation:

Given:

t1 = 10 min, t2 = 15 min

t = 6 min.

Latest HTET Updates

Last updated on Jun 6, 2025

-> The HTET TGT Applciation Portal will reopen on 1st June 2025 and close on 5th June 2025.

-> HTET Exam Date is out. HTET TGT Exam will be conducted on 26th and 27th July 2025

-> Candidates with a bachelor's degree and B.Ed. or equivalent qualification can apply for this recruitment.

-> The validity duration of certificates pertaining to passing Haryana TET has been extended for a lifetime.

-> Enhance your exam preparation with the HTET Previous Year Papers.

More Alternating Current Questions

More Electromagnetic Oscillations and Alternating Current Questions

Hot Links: teen patti joy 51 bonus teen patti - 3patti cards game teen patti jodi