Advertisements
Advertisements
प्रश्न
A 100 W electric lamp emits energy in the form of light at the rate 10 J per second. What percentage of electric energy does the lamp transform into light energy?
Advertisements
उत्तर
Given power of lamp = 100 watt
rate of dissipation of light = 10 J/s
Therefore, percentage of electrical energy converted into light energy = `10/100 xx 100%` = 10%
APPEARS IN
संबंधित प्रश्न
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A sailboat is moving due to wind energy.
No work is done by a force if the body
Define work.
How much work is done when a force of 1 N moves a body through a distance of 1 m in its own direction?
A uniform circular motion is an accelerated motion. Justify it.
Fill in the boxe to show the corresponding energy transformation.
State the energy changes which take place when A toy car with a wound spring moves on ground.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A wind-mill is lifting water from a well.
A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?
