Calculating Resistance (, I don't know any physics at all)

In summary: Once you have that table, plot the V and I data on a graph, and draw a straight line through the points. The slope of that line is the bulb resistance, in ohms. Alternatively, you can use the table of data to calculate the slope of the line. In summary, a variable voltage supply was used to measure the current and voltage of an incandescent bulb connected in a series circuit with a 10 \Omega resistor. The data was recorded in a table and a linear relationship between voltage and current was assumed. To determine the resistance of the bulb, one can either plot the data and calculate the slope of the line or use the data to calculate the slope directly. Additionally, Ohm's Law (
  • #1
itsastruggle
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Homework Statement



A variable voltage supply is connected in a series circuit with a 10 [tex]\Omega[/tex] resistor and an incandescent bulb.

An anmeter and a voltmeter were used to measure the current flowing through the bulb and the voltage across the bulb. By changing the voltage generated by the variable supply, the following measurements were taken:

Table:
Voltage (V): 1 ; 3.5 ; 5.6 ; 7.2 ; 9 ; 10.5
Current (mA): 60 ; 275 ; 450 ; 550 ; 640 ; 820

(Assume that the incandescent bulb has a linear relationship between its measured voltage and current).

1. How do I use the slope of the graphed data from the table to determine the resistance of the globe?

2. What is an alternative method (not using a graph) to analyse the measured voltage and current data to determine the resistance of the globe?

3. If the globe has a maximum of 12V, and the variable voltage is adjusted so that 12V is measured across the globe. How do you work out what the corresponding current measurement would be?

Homework Equations



Ohm's Law: V=IR


The Attempt at a Solution



--> I have no idea, I'm not familiar with physics at all! :(
 
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  • #2
itsastruggle said:

Homework Statement



A variable voltage supply is connected in a series circuit with a 10 [tex]\Omega[/tex] resistor and an incandescent bulb.

An anmeter and a voltmeter were used to measure the current flowing through the bulb and the voltage across the bulb. By changing the voltage generated by the variable supply, the following measurements were taken:

Table:
Voltage (V): 1 ; 3.5 ; 5.6 ; 7.2 ; 9 ; 10.5
Current (mA): 60 ; 275 ; 450 ; 550 ; 640 ; 820

(Assume that the incandescent bulb has a linear relationship between its measured voltage and current).

1. How do I use the slope of the graphed data from the table to determine the resistance of the globe?

2. What is an alternative method (not using a graph) to analyse the measured voltage and current data to determine the resistance of the globe?

3. If the globe has a maximum of 12V, and the variable voltage is adjusted so that 12V is measured across the globe. How do you work out what the corresponding current measurement would be?

Homework Equations



Ohm's Law: V=IR


The Attempt at a Solution



--> I have no idea, I'm not familiar with physics at all! :(

Welcome to the PF.

Start by making a table with 3 columns. You are given the data for the first two columns as V and I for the bulb. Fill in the 3rd column with the effective resistance of the bulb (use the Ohm's Law equation that you posted).
 

1. What is resistance?

Resistance is the measure of how much a material or device impedes the flow of electric current. It is measured in ohms (Ω).

2. How is resistance calculated?

Resistance is calculated using Ohm's Law, which states that resistance is equal to voltage divided by current. The formula for calculating resistance is R = V/I, where R is resistance in ohms, V is voltage in volts, and I is current in amperes.

3. What factors affect resistance?

The factors that affect resistance include the type of material, the length and thickness of the material, and the temperature. Materials with high resistivity and longer and thinner lengths will have higher resistance, while materials with lower resistivity and shorter and thicker lengths will have lower resistance.

4. How does resistance impact electric circuits?

Resistance is an important component in electric circuits as it determines the amount of current that can flow through the circuit. Higher resistance will decrease the current flow, while lower resistance will increase the current flow. It is also used in voltage dividers to control the amount of voltage in a circuit.

5. What are some real-life applications of calculating resistance?

Calculating resistance is important in various real-life applications, including designing and building electronic devices, determining the appropriate wire size for electrical circuits, and measuring the resistance of materials for safety and efficiency purposes. It is also used in industries such as telecommunications, power generation, and automotive engineering.

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