Answer:
B = 0.75 T
Explanation:
As we know that the force on a moving charge in magnetic field is given by the formula

here we have

here we know that



now from above equation we have


If it produces 20J of light energy in a second, then that 20J is the 10% of the supply that becomes useful output.
20 J/s = 10% of Supply
20 J/s = (0.1) x (Supply)
Divide each side by 0.1:
Supply = (20 J/s) / (0.1)
<em>Supply = 200 J/s </em>(200 watts)
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Here's something to think about: What could you do to make the lamp more efficient ? Answer: Use it for a heater !
If you use it for a heater, then the HEAT is the 'useful' part, and the light is the part that you really don't care about. Suddenly ... bada-boom ... the lamp is 90% efficient !
yes that is true because climate is over a period of time
Answer:
Explain why it is not advisable to sterilise a clinical thermometer on boiling water at normal atmospheric temperature. A clinical thermometer has small temperature range. The glass will crack/burst due to excessive pressure created by expansion of mercury.