Voltage Circuit Simulator

 

 

http://jersey.uoregon.edu/vlab/Voltage/

 

Some important information:

 

  1. What is the difference between ‘voltage’(V) and volts?

Voltage =

 

Volts =

 

  1. What is the effect of resistance on a circuit?

 

 

  1. How does increasing resistance (R) affect the flow of current?

 

 

 

  1. What does the unit of current (amperage) measure?  [Note:  amperage = I]

     

 

  1. How is the current converted into power in a light bulb? 

     

The problem consists of two parts:

  1. Find the formula which describes Ohm's Law; find the mathematical relationship between voltage (V), amperage (I), and resistance (R).
  2. Determine the amperage of the lightbulb.

The formula for OHM’S  LAW part will be discovered through a trial-and-error experiment:

 

1) You are given a circuit on which you may vary the voltage by :

a)      choosing from a variety of batteries

b)      changing the resistance by adding resistors to the circuit.

2) You will then turn on the switch, allowing current to flow through the circuit.

a)      If the resistance is too low, the lightbulb will receive too much current,

     and will explode.

b)      If the resistance is too great, the lightbulb will not receive enough current, and will not light.

c)      If the resistance is just right, the lightbulb will light up.

(Note: real light bulbs are not perfect ohmic resistors as is the case here 

and will light partially with any amount of current).

3)  If the lightbulb explodes or fails to light, turn off the switch (which automatically

     replaces the lightbulb) and try again.

Voltage Circuit Simulator                                                                              P. 2

The strategy: 

1.   First, concentrate on changing the resistance to get the lightbulb to turn on.

3.      Once you get a working circuit write down your values in the table below:

 

 

Trial #

Voltage

(V)

Resistance (R)

Amperage

(I)

1

6 V

 

2

2

12 V

 

2

3

18 V

 

2

4

24 V

 

2

 

4.      Change the value of the battery, and try again.

5.      Q: What do you predict would be the resistance necessary to light the bulb if the voltage was 36 V?

 

 

 

6.      Q:  Write a statement that describes how the resistance changes as the voltage is changed but the amperage remains constant.

 

 

 

 

7.      Q:  Look carefully at the completed data table.  Write a statement that explains how the voltage and resistance can  be used to determine the amperage

 

 

8.  This relationship is called Ohm’s law.  Which of these statements is the correct mathematical equation for this law?

            a)         I = VR                         b)  I = V/R                               c)  I = R/V                  

Use this circuit: http://jersey.uoregon.edu/vlab/Voltage/volt1.html to complete the following table:

Volts (V)

18

36

54

72

Amps (I)

3

3

3

3

Resistance  (R)

 

 

 

 

 

9.  Which statement correctly identifies this relationship?

a)         R = IR                          b)  R= V/I                                c)  R = I/V