Calculate the maximum current a 140 ohms, 1/2 watt

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SUMMARY

The maximum current that can safely flow through a 140 ohm, 1/2 watt resistor is calculated using the formula I = √(P/R), where P is the power rating and R is the resistance. Substituting the values, I = √(0.5W / 140Ω) results in a maximum current of approximately 0.134 mA. For the second part, the maximum electromotive force (e.m.f.) that can be applied without overheating is calculated using Ohm's Law, V = I * R, leading to a maximum voltage of approximately 18.8V.

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Bobzombie
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I have looked thought all my notes and books and can not find the formal on how to do this question. I'm slowly going out of my mind any help would be great

Calculate the maximum current a 140 ohms, 1/2 watt resistor can have flowing through it safely.
Enter answer: mA

Then the 2nd part of the question is

What is the maximum e.m.f. which may be applied to the resistor above without causing overheating?

Enter Part 2 answer: V
 
Physics news on Phys.org
Don't you have some fundamental equations that relate voltage (V), resistance (R), current (I), and power (W)? You'll need them.
 

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