If the pencil had an eraser would it have the same results?

Rubber is an insulator. With the amount of power generated here, you wouldn't see any result at all. Some high voltage stuff can overcome the insulation properties of rubber (which is why people that work on power lines can't just use rubber gloves) but that's incredibly unsafe for experimentation.

What is the fluid he pours into the cup?

Actually, you're both right: it's hot acid with added salt. The stuff he pours from the cooker is hot vinegar, and he adds a spoonful of salt. Both make the vinegar a better conductor.

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High school physics

Course: High school physics > Unit 12

Lesson 5: Discovery of resistors

Pencil resistor

Name: Pencil resistor
Uploaded: 2013-04-23T00:46:04Z
Description: A pencil causes a change in the deflection, similar to the effect of adding an electromagnet. Why?

Google Classroom

A pencil causes a change in the deflection, similar to the effect of adding an electromagnet. Why? Created by Brit Cruise.

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Alex
Posted 10 years ago. Direct link to Alex's post “If the pencil had an eras...”
If the pencil had an eraser would it have the same results?
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(3 votes)
Answer
- Stephen Brand
  Posted 9 years ago. Direct link to Stephen Brand's post “Rubber is an insulator. W...”
  Rubber is an insulator. With the amount of power generated here, you wouldn't see any result at all. Some high voltage stuff can overcome the insulation properties of rubber (which is why people that work on power lines can't just use rubber gloves) but that's incredibly unsafe for experimentation.
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  (2 votes)
Harshala Raj
Posted 8 years ago. Direct link to Harshala Raj's post “But if graphite is a cond...”
But if graphite is a conductor how can the pencil act as a resistor?
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(1 vote)
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rosawen2012
Posted 9 years ago. Direct link to rosawen2012's post “why is salt or vinegar im...”
why is salt or vinegar important??
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(2 votes)
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- 🚀The knowledge Hunter🔭
  Posted 8 years ago. Direct link to 🚀The knowledge Hunter🔭's post “Perhaps ts because they a...”
  Perhaps ts because they are good conductors of Electricity.
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  (0 votes)
🚹MrBacon🚹
Posted 9 years ago. Direct link to 🚹MrBacon🚹's post “I'm not to sure I underst...”
I'm not to sure I understand this but is a resister an insulator?
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(1 vote)
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Aiden Swayne
Posted 8 years ago. Direct link to Aiden Swayne's post “What would happen if you ...”
What would happen if you used a pen?
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(1 vote)
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jc99612510
Posted 9 years ago. Direct link to jc99612510's post “what does the pencil do s...”
what does the pencil do so the compass can move ?
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(1 vote)
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kiodro
Posted 10 years ago. Direct link to kiodro's post “What is the fluid he pour...”
What is the fluid he pours into the cup?
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(1 vote)
Answer
- Flanny
  Posted 10 years ago. Direct link to Flanny's post “Actually, you're both rig...”
  Actually, you're both right: it's hot acid with added salt. The stuff he pours from the cooker is hot vinegar, and he adds a spoonful of salt. Both make the vinegar a better conductor.
  Button navigates to signup page
  (2 votes)
Potato Productions
Posted 6 years ago. Direct link to Potato Productions's post “Won't the rubber band aro...”
Won't the rubber band around the cells affect the outcome?
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lucjustme
Posted 8 years ago. Direct link to lucjustme's post “But why a pencil, not a p...”
But why a pencil, not a pen?
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时若斯/anonymous
Posted 8 years ago. Direct link to 时若斯/anonymous's post “Why did he mark1 at the e...”
Why did he mark1 at the exact point?Why didn't he just mark1 at a random point?
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Video transcript

(coins clank on board) (hot water sizzling into cup) (teaspoon clanking on cup) (pencil scratching on pad)