How Is Thermal Energy Produced in a Resistor During Capacitor Discharge?

In summary, the conversation discusses finding the rate at which thermal energy is produced in a resistor and whether to use the inverse or inverse of the energy discharge equation. The expert advises using the power dissipation equation P=i2R, or P=V(t)I(t), where both V(t) and I(t) must be found.
  • #1
Daniiel
123
0
I have a quick question.
part of one of my questions asks
"Find the rate at which thermal energy is produced in a resistor"
i havn't included the whole question because i don't think it matters, its just like the last part of it
so we have
http://edugen.wiley.com/edugen/courses/crs1650/art/math/halliday8019c27/math148.gif
thats the discharge of energy out of the capacitor
so
would the inverse of that be the rate at which the energy is moved into the resistor
like
1/u = 2ce/q (i left out a lot of things but thatsl ike the base of it)

orr
do you juts switch the e^- to e^+
because e^- is decay and e^+ is growth

yeh I am just abit confused which is right, or if either is right haha.
thanks
 
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  • #2
Daniiel said:
I have a quick question.
part of one of my questions asks
"Find the rate at which thermal energy is produced in a resistor"
i havn't included the whole question because i don't think it matters,
It does matter. If the resistor is connected to the battery, thermal energy is constant with respect to time; if it is connected to a discharging capacitor (as seems to be the case here) then the thermal energy will be a function of time.
its just like the last part of it
so we have
http://edugen.wiley.com/edugen/courses/crs1650/art/math/halliday8019c27/math148.gif
thats the discharge of energy out of the capacitor
No. That's the energy stored in the capacitor at any time t.
so
would the inverse of that be the rate at which the energy is moved into the resistor
like
1/u = 2ce/q (i left out a lot of things but thatsl ike the base of it)

orr
do you juts switch the e^- to e^+
because e^- is decay and e^+ is growth

yeh I am just abit confused which is right, or if either is right haha.
thanks
None of the above. The rate at which energy is dissipated in the resistor (i.e. power dissipated) is given by
P = i2R, where i is the current in the resistor at a given time t. That's what you need to find an expression for.
 
  • #3
what about
P(t)= V(t) I(t)
is that alright aswell?
 
  • #4
Yes it is, but you will have to find two functions of time, V(t) and I(t). If you use P = I2R, you will need only I(t).
 
  • #5


The rate at which thermal energy is produced in a resistor can be calculated using the equation P = I^2R, where P is the power (rate of energy production), I is the current flowing through the resistor, and R is the resistance of the resistor. In the context of the discharge of a capacitor, the current through the resistor is related to the rate at which energy is moved into the resistor. The inverse of the discharge rate of the capacitor would not necessarily be the same as the rate at which energy is moved into the resistor, as the discharge rate also depends on the capacitance and charge of the capacitor. It is important to consider all relevant variables and equations when calculating the rate of thermal energy production in a resistor. Switching the e^- to e^+ may not be applicable in this situation, as it depends on the specific context and equations being used. It is important to carefully consider and understand the equations and variables involved in order to accurately calculate the rate of thermal energy production in a resistor.
 

1. What is a capacitor?

A capacitor is an electrical component that stores energy in an electric field. It is made up of two conductive plates separated by an insulating material called a dielectric.

2. How does a capacitor discharge?

A capacitor discharges when the stored energy in its electric field is released. This can happen through a physical connection or through a process called dielectric breakdown, where the insulating material breaks down and allows the energy to flow through.

3. What factors affect the discharge rate of a capacitor?

The discharge rate of a capacitor is affected by its capacitance, the voltage across the capacitor, and the resistance in the circuit. A higher capacitance and voltage will result in a slower discharge, while a higher resistance will result in a faster discharge.

4. What is the equation for calculating the discharge time of a capacitor?

The equation for calculating the discharge time of a capacitor is t = RC, where t is the time in seconds, R is the resistance in ohms, and C is the capacitance in farads. This equation assumes a simple RC circuit with no additional components.

5. Can a capacitor discharge completely?

Technically, a capacitor can discharge completely, but in practice, it is not recommended. A full discharge can cause damage to the capacitor and potentially create a hazard. It is best to discharge a capacitor to a safe voltage level, such as 0V, to avoid any potential risks.

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