AC Generator with Resistor: Exploring Kirchhoff's Loop Rule

In summary, the conversation discusses a circuit with a resistor and an AC generator with a given EMF. The Kirchhoff's Loop Rule is used to find a differential equation for the circuit, and the current as a function of time is determined by replacing dq/dt with i. The amplitude of the resulting alternating current is found to be E_m/R.
  • #1
Pete_01
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0

Homework Statement



A resistor of resistance R is connected to an AC
generator with EMF(t)=(EMF_max)sin((w_d)t). (a) Write
Kirchhoff's Loop Rule for this circuit at a particular
instant of time. Is your result a differential equation?
(b) Find the current as a function of time. Now assume
R=50 Ohm and EMF_max = 30.0 V. (c) What is the amplitude
of the resulting alternating current if the frequency of
the EMF is 1.00 kHz?

Homework Equations



V_R = R dQ(t)/dt

The Attempt at a Solution



Ok, so the differential equation I came up with is:
V_G + V_R = 0
E_m sin(w_d t) = R dQ(t)/dt

assuming that's correct how do I find the current as a function of time? Replace dq/dt with i? And after that?
 
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  • #2
And after that u get equation [tex]E_m sin(w_d t)=R I[/tex], hence [tex]I=\frac {E_m sin(w_d t)}{R}[/tex] and the amplitude of the ac current is [tex]\frac{E_m}{R}[/tex]

Something else, usually we apply Kirchoff's Law with currents and voltages and not with charges Q. Therefore MAYBE the correct answer to a) is by having replace dq/dt with I from the start and therefore the equation isn't a differential equation.
 
Last edited:
  • #3
Perfect, thank you!
 

1. What is an AC generator with resistor?

An AC generator with resistor is a device that converts mechanical energy into electrical energy by rotating a coil of wire in a magnetic field. The resistor is connected in series with the coil and serves to limit the current flowing through the circuit.

2. How does an AC generator with resistor work?

An AC generator with resistor works by rotating a coil of wire in a magnetic field. As the coil rotates, it cuts through the magnetic field, inducing an alternating current in the wire. This current is then limited by the resistor, which helps to maintain a constant voltage in the circuit.

3. What is Kirchhoff's Loop Rule?

Kirchhoff's Loop Rule, also known as Kirchhoff's second law, states that the sum of all voltage drops in a closed loop must equal the sum of all voltage rises. In other words, the total voltage in a closed circuit must be equal to the voltage supplied by the power source.

4. How is Kirchhoff's Loop Rule applied in an AC generator with resistor?

In an AC generator with resistor, Kirchhoff's Loop Rule is applied by considering the voltage drops and rises in the circuit. The voltage supplied by the generator is equal to the voltage drop across the resistor and the voltage rise across the coil. This ensures that the total voltage in the circuit remains constant.

5. What are some practical applications of AC generator with resistor?

AC generators with resistors are commonly used in power plants to generate electricity for homes and businesses. They are also used in electric motors, appliances, and electronic devices to convert electrical energy into mechanical energy. Additionally, AC generators are used in renewable energy sources such as wind turbines and hydroelectric power plants.

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