How to work it out? I've no idea.
need help! Watch
- Thread Starter
- 10-02-2017 18:54
- 10-02-2017 22:30
The best thing to do is to just think of the voltmeters as 10MΩ resistors, as that's all they're doing in this situation. You can also treat R and V2 as a single resistor by using the formula for resistors in parallel
If V1 has 4V, this means that the voltages are being shared in a 2:1 ratio between V1 and the R/V2 parallel bank. This means the ratio between their resistances must also be 2:1, so the total resistance of R and V2 must be half of the resistance of V1 (5V).
This gets you which you can solve to get R=10MΩ