What does a voltage drop mean?

  • 0 votes

In my physics revision guide on potential dividers its says that if the resistance is higher there is a bigger voltage drop? I'm just wondering what that means :S

Posted Sun 17th June, 2012 @ 08:01 by Terrie

3 Answers

  • 2 votes

This means when the resistance is highest then the voltage drops because the current is significantly decreased and if you use the V= I x R equation then you can see that the voltage decreases !!! Remember this when resistance increases current decreases becuase current is the flow of charge right, but if there is a high resistance then it restricts the flow of charge therefore giving you a lower current reading then when you sub the values into the equation you get a lower value for the potential difference!!

Anyway hopei havent confused you and if you need any clarification then plz comment again !!! =D

Answered Sun 17th June, 2012 @ 11:40 by Braniac
  • 1 vote

I see where your coming from but the thing is when resistance increase the current decrease by a lot so for example if I had a 25 ohm resistor put in a circuit with a current passing through it of  0.02 A then the p.d is gonna be decreased to say if you had equal resistance to current then it is going to be higher !! The current stays the same throughout the circuit (series) and if you put a resistor in it decrease the current at that point therefore decreasing the voltage across that resitor n resistors are not gonna be soo high !! if it is then the current is going to be very low for example if u did a pracatical n u used a 12v battery and also u put a resistor of 100 ohms the current is going to be 0.12 A which is quite low to say if u put a resistor of 3 ohms in! the resistor of 3 ohms will give u 4 amps ===> a big difference as u can c!!!

Answered Sun 17th June, 2012 @ 16:23 by Braniac
  • 0 votes

thanks! oh so by 'voltage drop' it means like voltage decrease? and also, i'm slightly still confused though because using the V = I x R equation, even if the current falls because the resistance is high, wont the voltage still be significantly high because at least the R is a large number? 

Answered Sun 17th June, 2012 @ 13:14 by Terrie