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Drizzy
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Homework Statement
(My english is not good)
If I have a battery that is 4v why isn't U = 4 ?
What you are calling 'U' appears to be a lower case 'v'. In any event, 'v' is called the 'voltage' in English.Drizzy said:U=RI I don't know what it is called in english
Grim Arrow said:Becouse the voltage U gets divided between the resistors and so if u have two resistors and 4 volts battery, the voltage gets divided between the two resistors. And so u can have 2volts on one resistor and 2 on the other. Or 3 on one resistor and 1 on the other. It deppends entirely on the resistances values.
Drizzy said:https://www.google.se/search?q=sluten+krets&rlz=1C1_____enSE663SE663&es_sm=93&source=lnms&tbm=isch&sa=X&ved=0CAcQ_AUoAWoVChMI9qSA7Lr3yAIVSwwsCh0p0wfM&biw=1366&bih=643#imgrc=1c4HK9RkOMo_SM:
There is resistance and current but why isn't U equal to the volt of the battery?
What voltage is: Imagine 2 atoms divided by a distance. Atom A and atom B. Atom A looses some of the electrons therefore it becomes more positive(the positive charge of the protons becomes less compensated). Its electric field becomes stronger. Now you should know that every atom has a positive core and that core uses electric field to attract electrons in. However, since both atoms before were in equilibrium and now suddently A looses electrons it field grows and the equilibrium is broken. In order to restore it, A will attract some of the electrons from B until both atoms have the same positive charge. At that point equilibrium is restored and every single electron who left B will make it more positive than A and B will attract it back. ! Take in mind that i use single atoms in my argumentation. In battery is the same but there are billions of atoms more. So Voltage is the work done by the electric field to move an electron from (in this case) B to A. Also B may be 3volts and A6volts. There still will be potential difference of 3volts between them and current will still flow. What happens is that A becomes less positive as it is accepting electrons and B becomes more positive becouse it is giving away electrons leaving behind more uncompensated positive charge. Current will flow until A and B has the same voltage: A-6,5,4 5volts B-3,4,4.5volts. The voltage between this two points is given by V=VA-VB. Does this helped you, let me know. Also you can see Atom steucture in internetDrizzy said:But what is U? I don't understand what it is. The only thing I see is a letter not what it actakly is
This is because the voltage (V) of a battery is a measure of potential difference, while the potential (U) is a measure of electrical potential energy. The two are related by the equation U = QV, where Q is the charge. Therefore, the potential difference of 4V does not necessarily mean that the potential energy is also 4, as it depends on the amount of charge in the system.
Yes, it is possible for U to be equal to V in certain situations. This occurs when there is no charge in the system, meaning Q = 0. In this case, the equation becomes U = 0V, which means that the potential energy is also 0.
The amount of charge in a system directly affects the potential energy and voltage. As mentioned before, the equation U = QV shows that the two are directly proportional. This means that an increase in charge will result in an increase in both potential energy and voltage, while a decrease in charge will result in a decrease in both.
Understanding the difference between potential and voltage is crucial in order to accurately measure and predict the behavior of a battery. While voltage is a measurable quantity, potential is a concept that helps us understand the energy stored in a system. By understanding this difference, we can make informed decisions about the use and maintenance of batteries.
No, the potential and voltage of a battery are directly related and cannot be changed independently. The only way to change the potential is to change the amount of charge in the system, which will also result in a change in voltage. However, the potential can be affected by external factors such as temperature and resistance, which can indirectly impact the voltage of a battery.