## Research question:

How will increasing the voltage (v) to 5v, 10v, 20v, 35v, and then 50v affect the amount of current (Amps) measured by an ammeter, keeping the resistance (ohms) at 12 ohms and the wire length of 10cm constant, in a series circuit to prove ohms law?

## Background information on Ohm’s law:

Ohms law can be used to identify the relationship between voltage, current, and resistance in any DC electrical circuit discovered by a German physicist named, Georg Ohm. This law states that voltage is equal to the product of the total current and the total resistance.

The equation for this law is often presented in a triangle where the voltage is on the top, current and resistance are on the bottom with only a line separating them;

In order to find the voltage, you must multiply the current and the resistance, to find the current or the resistance you must divide the voltage by either current (to find resistance) or resistance (to find current).

## Hypothesis:

I predict that the higher the voltage, the higher the amount of current will be. I think this because there will be more power distributed throughout the series circuit due to the fact of a higher voltage, indicating that the current would run at a faster pace even with the resistance of 12 ohms.

If the voltage is 5 and the resistance is 12 ohms, the current would move at a slower pace and would decrease because the resistance causes that slower pace as a result of using more energy from the battery/voltage.

## Variables:

** Independent variable:** The independent variable is the amount of voltage; 5V, 10V, 20V, 35V, and 50V. ** Dependent variable:** The dependent variable is the amount of current that is flowing in a series circuit measured in AMPS or A.

## Controlled variable:

What will be kept the same | Why will it be kept the same | How will it be kept the same |

I will keep the amount of resistance the same. | I will keep the amount of resistance the same to conduct an accurate experiment. | I will keep the resistance the same by setting the resistor to 12 ohms. |

I will keep the length of the wires the same. | I will keep the length of the wires the same to have a fair trial. | I will keep the length of the wires the same by only having wires that are 10 cm. |

I will keep the place of the ammeter in the circuit the same. | I will keep the place of the ammeter in a circuit the same because the readings could possibly change in different positions and have accurate results. | I will keep the place of the ammeter in a circuit the same by building the circuit and not adding anything extra to it that will change the spot of the ammeter. |

I will keep the battery the same. | I will keep the battery the same to have a fair trial, also because if different batteries are used the power coming out could be different even with the same voltage. | I will keep the battery the same by not taking it out of the circuit once it’s in and only changing the voltage when needed. |

I will keep the place of the resistor the same. | I will keep the place of the resistor the same because the results could be compromised, so to avoid that and get accurate results I will keep the resistor in the same place in the series circuit. | I will keep the place of the resistor the same by building the circuit and not adding anything extra to the circuit that could change the spot of the resistor. |

## Materials:

- Battery X1
- Resistor X1
- Ammeter X1
- Wires X7 (use more if needed)
- Switch X1 (optional, I didn’t use one as it is not mandatory)

## Safety:

When undertaking this experiment make sure to take safety precautions to be on the safe side and avoid any danger. Firstly, do not have any liquids around the circuit because if it spills it can cause major issues to the circuit such as creating sparks and or start possibly a fire, this is because liquids increase the conductivity of the electrical flow.

Ensure that all loose articles are not hanging from any place in your body like a tie, and if you have long hair tie it back so nothing is touching the circuit as it can irritate you and can be dangerous.

Lastly, check all the materials are in perfect condition to avoid any dangers that could happen, especially check the battery because if it’s not in perfect condition it can explode and become very harmful.

## Method:

## Graph

## Results Table:

Voltage (v) | Resistance (ohms) | Current (amps/ a) |

5 | 12 | 0.42 |

10 | 12 | 0.83 |

20 | 12 | 1.67 |

35 | 12 | 2.92 |

50 | 12 | 4.17 |

## Experiment conclusion:

The data shows that the higher the voltage, then the higher current, meaning that the voltage is directly proportional to the current, which is what ohms law states. This means When the voltage increases the current will always increase as long as there is no resistance or if the resistance stays the same.

For example, in my experiment, I increased the voltage from 5v,10v,20v,35v, to 50v while keeping the resistance the same so the current increased every time the voltage increased.

The law was proven for every trial I performed and this can be shown when dividing the voltage by the current to get the resistance. My hypothesis was correct, in my hypothesis, I claimed that the higher the voltage, the higher the current. As shown above, the voltage is directly proportional to the current.

One example from my results is when I increased the voltage to 50v I then divided that number by the current which was 4.17 to give me the amount of resistance which is 12ohms.

## Experiment evaluation:

The overall experiment went well, and it succeeded the purpose of the trial which was how changing the voltage could affect the amount of current flowing in a series circuit while being able to prove ohms law. A weakness in my experiment is my graph of the results.

My graph was my weakness in this experiment because the graph should have mentioned the resistance as it is a key fact of proving ohms law.

One improvement I could have done to make the experiment better and get more accurate results was if I had added a voltammeter to the series circuit.

A voltammeter would read the amount of voltage that is given out of the battery used, therefore if I used a voltammeter, I could have ensured that the amount of voltage that was given out of the battery was correct and the results would be more accurate.

Thanks

This is good