83Views6Replies

# How to show change in current? Answered

I am making a trainer kit for my students. The kit will show the operation of resistors in series and in parallel.
In series circuit I connected an LDR with a piezo buzzer which shows the change in voltage.
But the same thing does not work in the parallel thing. The change in current does not affect the buzzer.
Any Idea what can be done to solve the problem is appreciated?

Tags:

## Discussions

A compass placed across a North - South wire will indicate current by
deflecting East - West in proportion to current in wire intensity.

A

Actually using a DMM in voltage mode across one resistor will show a difference in voltage from A to B and you can calculate the current thus: point A ---[R]--- point B
I = V / R Knowing the value of the resistor (R) and taking the voltage (V) reading from the meter you can get the current (I). How "I" represents current and not "C" is a whole other lesson. Divide and viola! Basic Ohms law.

Here's a great link to demonstrate: http://www.sengpielaudio.com/calculator-ohmslaw.htm

Easiest way is to put a meter in the line. Small changes of current can be measured.