ohms law Work sheet 16d?

Re: ohms law Work sheet 16d?

by Bartholomew Milne -
Number of replies: 0

Hello Leon, I am not sure whether you mean a particular question or not.

Question 1 is a simple voltage divider problem. The total resistance is 65 Ω, and the internal EMF is 65 V. That, and the individual resistor values is enough to calculate the voltage drop across each resistor.

Question 2: First of all, it does not matter what order the EMF and internal resistance are in.

I'd suggest redrawing the circuit, as it's drawn in a very confusing way.

In this case, you are asked to calculate voltages relative to point 'A'. This is similar to problems where you're asked to calculate voltages 'relative to ground'. In this case point 'A' is our ground, or zero volt reference. In other words, the voltage at point A is considered zero by definition.

In order to solve this problem, you'll need to compute the total current in the circuit by simplifying the resistor network. Then you can work the problem through.

Question 3: This one is more complicated, but is solvable. Start at point E.
1. Make an equation for V_F in terms of V_C using the voltage divider equation.
2. Make an equation for V_E in terms of V_D using the parallel resistance and the voltage divider equations.
3. Make an equation for V_D in terms of V_C using the parallel resistance and the voltage divider equations.
4. Make an equation for V_C in terms of V_B using the parallel resistance and the voltage divider equations.
5. Make an equation for V_B in terms of the 147 V EMF using the voltage divider equations.

Then work out the voltages by "back substitution".

Let me know if you have any more questions.

I attach some files with partial workings.

Thanks
Bart