Electric Circuit: What Slope Tells You

AI Thread Summary
The discussion focuses on understanding the relationship between length and resistance in an electric circuit, emphasizing that increased length leads to higher resistance due to the material's resistivity. It also highlights Ohm's Law, which states that current is directly proportional to voltage and inversely proportional to resistance. The slope of a length vs. resistance graph indicates the resistivity of the material, while the slope of an inverse resistance vs. current graph reveals the relationship between current and resistance. Participants seek clarification on graphing techniques and formulas, particularly how to rearrange Ohm's Law into a linear format for plotting. Overall, the conversation aims to deepen the understanding of circuit behavior through graphical analysis.
AddversitY
Messages
19
Reaction score
0
What does the slope of a length vs. resistance graph tell you?
Slope=?

What does the slope of an inverse resistance vs. current graph tell you?
Slope=?

__________________________________________________________________

Here's what I had to do for my lab:

1: Construct a circuit where I connect a clip onto a wire that allows electricity to flow. Move the clip down the meter stick until you reach 100cm. Result: The farther I moved the clip down the wire the dimmer my light bulb got. The power source was a battery.

2: Measure and record the voltage of the circuit across the battery - this needs to only to be done once. Result: The voltage stayed the same (I do not know if that is correct).

3: Instert an ammeter and measure and record in a table the corresponding current (I) at each position (l).

4: Predict the Resistance (R) at each position.

5: Construct the following:
A) Length (l) vs Resistance (R)
B) Inverse Resistance (1/R) vs Current (I)

My graphs looked like the following: (If anybody has any recommendations on where to create graphs PLEASE tell me, this site isn't too great.)
A = http://www.chartgo.com/share.do?id=d886b9a8aa
B = http://www.chartgo.com/share.do?id=94f8b0fdaa
 
Physics news on Phys.org
Firstly how does resistance relate to length? (think of resistivity of a material)

Secondly what does Ohm's law state?
 
rock.freak667 said:
Firstly how does resistance relate to length? (think of resistivity of a material)

Secondly what does Ohm's law state?

1: The greater the length results in more resistance.

2: Ohm's law: The current passing through a conductor between two points is directly proportional to the potential difference (i.e. voltage drop or voltage) across the two points, and inversely proportional to the resistance between them.
 
AddversitY said:
1: The greater the length results in more resistance.

So what formula relates resistance and length?

AddversitY said:
2: Ohm's law: The current passing through a conductor between two points is directly proportional to the potential difference (i.e. voltage drop or voltage) across the two points, and inversely proportional to the resistance between them.

So then you have V = IR, how would you rearrange the formula to get in the form Y=MX where you plotted Y against X?
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top