V Ir Example
Now using this resistance value to calculate the voltage when current was 20 ma.
V ir example. The battery is a 12 volt battery and the resistance of the resistor is 600 ohm. One can determine a value of current i for a given value of applied voltage v from the curve but not from ohm s law since the value of resistance is not constant as a function of applied voltage. V 0 2 1200 240v. Solution to example 1 substitute r by 2 and v by 6 in ohm s law v r i.
As seen in the figure the current does not increase linearly with applied voltage for a diode. Better funny explanation of ohm s law. Voltage dropped v1 v2 18 v 9 v 9 volts. V is the voltage in volts v i is the current in amperes or amps a r is the resistance in ohms ω greek letter omega thus if you know the current and resistance you can use the formula to find the voltage.
Click image to enlarge. This expression for v can be interpreted as the voltage drop across a resistor produced by the flow of current i. The best way to teach how to use it is by example. An example is the p n junction diode curve at right.
Load analogy to understand the ohm s law. Below is a very simple circuit with a battery and a resistor. By using algebra you can rearrange the variables to suit your needs. How much current flows through the circuit.
A 1 2k resistor passes a current of 0 2a what is the voltage across it. For instance the headlight in example 1 above has an. Simple funny explanation or another funny way to explain ohm s law. The phrase ir drop is often used for this voltage.
Hope you find some good v ir solved examples here. V i r. For more ohm s law solved example and ohm s law principle stay in touch with us. Our final calculation will again use ohm s law to give us the total voltage drop for each resistor in the form of v ir which looks like this.
Example 1 find the current i through a resistor of resistance r 2 ω if the voltage across the resistor is 6 v. In the example below we have two known variables the total voltage and the voltage drop across r1. Click image to enlarge. 6 2 i solve for i i 6 2 3 a example 2 in the circuit below resistors r1 and r2 are in series and have resistances of 5 ω and 10 ω respectively.