10. The power output of a lamp is 6W. How much energy does the lamp give out in 2 minutes? (Work, Power & Energy,power and energy)
Correct answer: C. 720 j
- A. 3 j
- B. 120 j
- C. 720 j
- D. 430 j
Explanation
Explanation: Power (P) is the rate of energy transfer, measured in Joules per second (J/s). So, a 6W lamp transfers energy at a rate of 6 J/s. In 2 minutes (120 seconds), the total energy transferred would be 6 J/s * 120 s = 720 J.Incorrect Options:(a) This underestimates the energy transfer by a factor of 240. The lamp gives out energy at a much faster rate than 3 J every 2 minutes.(b) This only considers the power output for 1 minute. To calculate the energy transferred in 2 minutes, we need to multiply the power by the total time.(d) This is an arbitrary number and doesn't follow the logic of power and time.
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About Work and Energy
Work transfers energy when a force causes displacement, while kinetic energy, gravitational potential energy and power describe motion, position and the rate of energy transfer. The work-energy theorem links net work with change in kinetic energy, and efficiency accounts for energy losses rather than treating them as energy destruction.
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