1
vote
2answers
32 views

Finding power in series circuit

A resistor of resistance 12 ohms is connected in series with a cell of negligible internal resistance. The power dissipated in the resistor is P. The resistor is replaced with a resistor of resistance ...
0
votes
1answer
36 views

Getting maximum power/brightness from 5 lightbulbs with different resistances [closed]

Hi I am trying to figure out the best way to arrange 5 lightbulbs to get all of them to have the maximum brightness with a 30V battery. The 5 five lightbulbs have different resistances: 3ohms, 6ohms, ...
-1
votes
2answers
43 views

Why doesn't a resistor dissipate reactive power? [closed]

Is there a (preferably microscopic) explanation for why a resistor does not dissipate reactive power?
1
vote
3answers
139 views

How does Ohm's law apply to superconductors?

As radio amateurs we've all learned the various relationships of power, voltage, current and resistance as expressed in Ohm's Law. My question relates to the following simple circuit showing an ideal ...
2
votes
2answers
81 views

Difference between $I^2R$ and $V^2/R$ and $VI$ for measuring power $P$

We use $I^2R$ or $V^2/R$ or $VI$ for measuring power $P$. Are all of these applicable for all circuits? I have seen in some circuit $V^2/R$ is not equal to $I^2R$. Why is that?
0
votes
0answers
235 views

What would the graph between P (power) and i (current) look like if the graph between V (potential difference) and i is parabolic?

The answer is same... That us the graph between P and I will also be a parabola.... Similar to the graph between V and I. But how? Can anyone explain through mathematical approach ? I used ...
1
vote
0answers
199 views

Power dissipated through resistor in RC circuit with charged Capacitor [closed]

so here's the problem: A simple RC circuit where the capacitor has been charged, and two resistors are in parallel configuration. How does one find the power (as function of time) through any of the ...
0
votes
1answer
38 views

Quadrupling Power in a Circuit

If I have a heating wire with resistance $R$ to be connected across a constant potential difference $V$, it would seem like cutting the wire into two (thus each having half the resistance) and ...
1
vote
1answer
872 views

Power dissipated on internal resistance of short-circuited voltage source

Suppose we have a voltage source with an EMF of $\mathcal{E}$ and an internal resistance $R$. If we connect to it a perfect wire with zero resistance, we get a short circuit. The value of the current ...
-1
votes
3answers
86 views

Electric Current Power Calculations [closed]

With regards to the equations: $P=VI$ ; $P=V^2/R$ and $P=I^2R$, if you are given $P$, $V$, $I$ and $R$ for a circuit, how do you know which equation to use? Does the use of an equation have to do ...
4
votes
5answers
510 views

Intuitively, Why is Power Proportional to $I^2R$

As the resistance of a circuit goes down, the power increases because the current increases, assuming constant voltage. Why is this? I feel like resistance and current are inversely proportional, so ...
0
votes
4answers
7k views

Power dissipated in Series versus Parallel

Do two resistors in parallel dissipate more heat per unit time for an applied voltage when compared to two resistors in series?
0
votes
2answers
120 views

In which direction should flow of electric current be taken while solving problems?

Consider a simple circuit with a battery of $\theta\ \text V$s, and two resistors of $R_1 \ \Omega$s and $R_2\ \Omega$s connected in series. Let us assume that $R_1$ is connected nearer to the ...