Voltmeter Reading for Ohm's Law Problem

  • Thread starter Thread starter gex
  • Start date Start date
  • Tags Tags
    Voltmeter
AI Thread Summary
The discussion revolves around solving an Ohm's Law problem where the provided answer is ɛ/2, but the original poster struggles to reach this conclusion. They mention using KVL and note that an ideal voltmeter has infinite resistance, preventing current flow into it. A suggestion is made to improve the clarity of shared images or to type out the work for better understanding. Additionally, the importance of using LaTeX for mathematical expressions is highlighted. The thread is ultimately locked, indicating no further responses will be accepted.
gex
Messages
36
Reaction score
2

Homework Statement


2iW6Doc


Homework Equations


Ohm's Law (V=IR)

The Attempt at a Solution


FMFlQ

These are my two attempts at getting to the solution. I'm really finding it difficult to tackle this question (our teacher gave it as an optional challenge). The provided answer on the worksheet is ɛ/2, but I have no clue how to get there. Any help is much appreciated.
 

Attachments

  • Question.jpg
    Question.jpg
    18.5 KB · Views: 389
  • Attempt 1.jpg
    Attempt 1.jpg
    20.4 KB · Views: 481
  • Attempt 2.jpg
    Attempt 2.jpg
    16.8 KB · Views: 464
Physics news on Phys.org
An ideal voltmeter is one that has infinite resistance. Use KVL, the resistor to the rightmost (nearest to terminal A) is short circuited anyway, so you are left with two resistors of equal resistance.

All measuring devices conncected to a circuit adveresly effect it, ideal ones dont. Since a voltage measurement is always made parallel to elements there must not be any current flowing into the voltmeter I believe, and this is achieved by having an infinite resistance. :-)
 
Hi Gex,

Unfortunately your images are essentially unreadable. Please make a new thread and type out your work or provide better pictures (preferably the former). I highly recommend learning a little bit of LaTeX. It greatly helps with inserting math into your posts. We have a primer for it here: https://www.physicsforums.com/help/latexhelp/

Thread locked.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...

Similar threads

Back
Top