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T

turbomen

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A special LED has a forward voltage of 2.2 V, and requires 10mA to produce its rated output. It is to be powered using a 9 V battery:

a. Calculate the value of the LED’s series current-limiting resistor











b. Calculate the exact power supplied by the battery in mW








c. Calculate the power dissipated by the LED in mW







d. Calculate the power dissipated (heat) by the resistor in mW






 
P

pushrod

  • Thread Starter Thread Starter
  • #2
A special LED has a forward voltage of 2.2 V, and requires 10mA to produce its rated output. It is to be powered using a 9 V battery:

a. Calculate the value of the LED’s series current-limiting resistor


r=v/i ,

r=6.8/0.01








b. Calculate the exact power supplied by the battery in mW


p=i*v

p=0.01*9





c. Calculate the power dissipated by the LED in mW

p=i*v

p=0.01*2.2





d. Calculate the power dissipated (heat) by the resistor in mW

is the difference between power supplied by battery and power used by LED
Homework for tomorrow?:)
 
G

Guest123

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  • #3
Do you not have course notes to revise from???
 
P

pushrod

  • Thread Starter Thread Starter
  • #4
Hmmm i answered 4 parts and corrected others and didn't even get a thanks, i'm not going to play any more:p ;)

TBH Turbomen you should have a go yourself and then ask if you have got the right answer or are on the right track. That way you will learn much more than just someone taking you straight to the right answer:)
 
T

turbomen

  • Thread Starter Thread Starter
  • #5
Do you not have course notes to revise from???


I have some course notes to revise from but they are always concentrate on the lab work.

Hmmm i answered 4 parts and corrected others and didn't even get a thanks, i'm not going to play any more:p ;)

TBH Turbomen you should have a go yourself and then ask if you have got the right answer or are on the right track. That way you will learn much more than just someone taking you straight to the right answer:)

Sorry, it is a time difference between you and me. So, I am late to give thank you.

Homework for tomorrow?:)
Sorry, it is a electronics test review.
 
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