Question based on a video (battery and voltage)

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  • #36
What are these pictures about?
 
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  • #37
gracy said:
And even if Q1 isn't greater final potential at x will still be greater than final potential at y. Right?
I don't think so. If Q1 is greater, then only Vxf>Vyf. You can see it here.
Screenshot_2016-02-13-14-43-29.png
Screenshot_2016-02-13-14-43-38.png
 
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  • #38
##q_{1f}## + ##q_{2f}## =##Q_{1f}## - ##Q_{2f}##

If ##Q_{1f}## < ##Q_{2f}##

It means ##q_{1f}## < ##q_{2f}##

But it does not tell much about polarity of ##q_{1f}##.
 
  • #39
gracy said:
##q_{1f}## + ##q_{2f}## =##Q_{1f}## - ##Q_{2f}##

If ##Q_{1f}## < ##Q_{2f}##

It means ##q_{1f}## < ##q_{2f}##

But it does not tell much about polarity of ##q_{1f}##.
See #37. The polarity of 10uF has changed. If Q1 is more, it will retain its polarity.
 
  • #40
If Q1 is greater, Vxf>Vyf. In #37, Q1(charge on 10uF)is less than Q2(charge on 5uF). Hence, polarity of C1(10uF) changed, making Vxf<Vyf.
 
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  • #41
I am unable to comprehend those pictures in post #37.
 
  • #42
cnh1995 said:
eater, Vxf>Vyf. In #37, Q1(charge on 10uF)is less than Q2(charge on 5uF). Hence, polarity of C1(10uF) changed, making Vxf<Vyf.

How one Can prove it ? I mean besides experimentally.
 
  • #43
gracy said:
There will be potential difference between points x and y given by (Q1−Q2)/(C1+C2)
If Q1<Q2, Vxy will be negative i.e Vx<Vy.
 
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  • #44
gracy said:
I am unable to comprehend those pictures in post #37.
It is a simulation result. It is an example of the case 3 in that video. In that circuit, Q1(charge on 10uF) is less than Q2(charge on 5uF) but initially Vx>Vy. When the middle switch is closed, it becomes the case 3. You can see the polarity of the 10uF reversed in the steady state, making Vx<Vy.
 
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  • #45
Can you give me link to that simulation site?
 
  • #46
gracy said:
Can you give me link to that simulation site?
It is an android app on my phone.
 
  • #47
gracy,

When you said the following (way) back in Post #30,
gracy said:
There will be potential different between points x and y given by ##\frac{Q1-Q2}{C1+C2}##
Right?
I thought it was clear to you as to why Vx > Vy . ##\ ## After all, Vx − Vy = (Q1 − Q2)/(C1 + C2) .
 
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  • #48
I thought this formula is for potential difference and it is not particularly ##V_x## - ##V_y## rather ##V_+## - ##V_-##. I know it's bit odd but that's what I thought.
 
  • #49
gracy said:
I thought this formula is for potential difference and it is not particularly ##V_x## - ##V_y## rather ##V_+## - ##V_-##. I know it's bit odd but that's what I thought.
They are the very same thing in this case.
 
  • #50
When I thought it is ##V_+## - ##V_-##

By ##V_+## I mean potential at either x or y whichever is at greater (positive potential ).

(##Q_1## - ##Q_2##)/(##C_1## + ##C_2## )This formula just gives potential difference and does not specify anything about which point is at greater potential.This is what I thought.

I wrote there will be potential different between points x and y given by (##Q_1## - ##Q_2##)/(##C_1## + ##C_2## ) because at that time I knew x is at greater potential.
 
  • #51
gracy said:
When I thought it is ##V_+## - ##V_-##

By ##V_+## I mean potential at either x or y whichever is at greater (positive potential ).

(##Q_1## - ##Q_2##)/(##C_1## + ##C_2## )This formula just gives potential difference and does not specify anything about which point is at greater potential.This is what thought.
First, think.

The above formula does specify which is at higher potential.
If ##\ Q_1< Q_2 \,,\ ## then ##\ Q_1- Q_2 \ ## and ##\ V_x- V_y \ ## are negative meaning Vy becomes the V+.

I wrote there will be potential different between points x and y given by (##Q_1## - ##Q_2##)/(##C_1## + ##C_2## ) because at that time I knew x is at greater potential.
 
<h2>1. What is the relationship between battery and voltage?</h2><p>The battery is the source of electrical energy, while voltage is the measure of the potential difference between two points in a circuit. The battery's voltage determines how much energy it can provide to the circuit.</p><h2>2. How does the voltage of a battery affect the performance of a device?</h2><p>The voltage of a battery directly affects the performance of a device. A higher voltage can make a device run faster or provide more power, while a lower voltage can cause it to run slower or not work at all.</p><h2>3. Can the voltage of a battery change over time?</h2><p>Yes, the voltage of a battery can change over time. As a battery is used, its voltage will decrease until it eventually runs out of energy. Additionally, factors such as temperature and age can also affect the voltage of a battery.</p><h2>4. How do different types of batteries affect voltage?</h2><p>Different types of batteries can have different voltages. For example, a standard AA battery typically has a voltage of 1.5 volts, while a car battery can have a voltage of 12 volts. The materials and design of the battery determine its voltage.</p><h2>5. What is the difference between voltage and current?</h2><p>Voltage and current are two different properties of electricity. Voltage is the measure of potential difference between two points, while current is the measure of the flow of electric charge. In other words, voltage is like the pressure that pushes the electricity through a circuit, while current is the amount of electricity flowing through the circuit.</p>

1. What is the relationship between battery and voltage?

The battery is the source of electrical energy, while voltage is the measure of the potential difference between two points in a circuit. The battery's voltage determines how much energy it can provide to the circuit.

2. How does the voltage of a battery affect the performance of a device?

The voltage of a battery directly affects the performance of a device. A higher voltage can make a device run faster or provide more power, while a lower voltage can cause it to run slower or not work at all.

3. Can the voltage of a battery change over time?

Yes, the voltage of a battery can change over time. As a battery is used, its voltage will decrease until it eventually runs out of energy. Additionally, factors such as temperature and age can also affect the voltage of a battery.

4. How do different types of batteries affect voltage?

Different types of batteries can have different voltages. For example, a standard AA battery typically has a voltage of 1.5 volts, while a car battery can have a voltage of 12 volts. The materials and design of the battery determine its voltage.

5. What is the difference between voltage and current?

Voltage and current are two different properties of electricity. Voltage is the measure of potential difference between two points, while current is the measure of the flow of electric charge. In other words, voltage is like the pressure that pushes the electricity through a circuit, while current is the amount of electricity flowing through the circuit.

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