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Suresh purchases a table lamp for study. The table lamp consumes 960 J of electrical energy in 16 s. What is its power?

  1. 60 W
  2. 45 W
  3. 50 W
  4. 48 W

Answer (Detailed Solution Below)

Option 1 : 60 W
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Detailed Solution

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The correct answer is 60W.

Key Points

Explanation:

Power – It is defined as the rate of doing work.

  • Where, P = power, W = work done, and t = time.
  • Now,
    • Time = 16 s
    • Work done = Energy consumed by the lamp = 960 J
    • Power = 960/16 = 60 Js-1 = 60 W

 

As Work done = Force × Distance

Force = mass × acceleration

Dimensional formula of force (F) = [M] × [LT-2] = [MLT-2]

Dimensional formula of work (W) = [ML2T-2]

Dimensional formula of time (t) = [T1]

The dimensional formula of power P is [ML2T-3].

Additional Information

  • Power = Power is the rate at which work is done = Work/Time
  • Horsepower: The unit used to measure power in the industrial sector.
  • 1 Horsepower = 746 Watt.
  • 1 Kilowatt Power: 1000 Joule work performed in 1 second is 1-kilowatt power.
  • 1 kW h = 3.6 × 106 J

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Exams Tests Super Practice

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