Shock Value/Circuit Lab Question Marathon

[simicartan]

Restarting this again

A battery with EMF 8 V is connected to a resistor with resistance 5 kOhms. A voltage of 7.9 V is measured across its terminals. Find the internal resistance of the battery.

okay but what is the answer though?

[mdv2o5]

Restarting this again

A battery with EMF 8 V is connected to a resistor with resistance 5 kOhms. A voltage of 7.9 V is measured across its terminals. Find the internal resistance of the battery.

okay but what is the answer though?

Answer (Also given earlier) (Click to Show Hidden Text)

63.3 ohms.

7.9 V is dropped across the 5k resistor which gives a total current of 1.58 mA. Since the internal resistance is modeled as a resistor in series with the ideal 8V voltage source and the 5k resistor, we know the total current going through the "internal" resistor is also 1.58 mA. We also know that there is a 0.1V drop across this internal resistor. Ohms law gives us R = V/I = 0.1V/1.58mA = 63.3 ohms.

Restarting this since it's been a while:

63.3 ohms (although with that kind of internal resistance, you should probably get a new battery)

Let's do some physics. How many electrons flow through a point on a wire carrying 30 mA in 30 seconds?

Click to Show Answer

30 mA * 1 A/1000 mA * 30 seconds * 6.24E18 electrons/C = 5.6E18 electrons

Looks good to me! Your turn?

[UTF-8 U+6211 U+662F]

What is Millman's theorem?

[Things2do]

What is Millman's theorem?

Need Me To Be More Specific?[size=3]You probably do, but...[/size] (Click to Show Hidden Text)

Millman's theorem, or the parallel generator theorem, is a method to simplify the solution of a circuit.

[UTF-8 U+6211 U+662F]

What is Millman's theorem?

Need Me To Be More Specific?[size=3]You probably do, but...[/size] (Click to Show Hidden Text)

Millman's theorem, or the parallel generator theorem, is a method to simplify the solution of a circuit.

Nope, your turn

[Things2do]

1: What is the chemical formula of lodeston?
2: What is a electromagnet, and how does it work?

[mdv2o5]

1: What is the chemical formula of lodeston?
2: What is a electromagnet, and how does it work?

Answer (Click to Show Hidden Text)

1. Lodestone has the formula Fe[sub]3[/sub]O[sub]4[/sub] with one of the iron atoms being in the +2 state and the other 2 in the +3 oxidation state.
2. An electromagnet is a device that produces a magnetic field from an electric current. Without going into too much physics, electric current flowing through a wire creates a magnetic field around the wire in a direction that is consistent with the right-hand-rule. By winding the wire into a helix, you add together these smaller magnetic fields into a stronger magnetic field passing through the axis of the helix. This allows you to control the magnetic field by controlling the current you pass through the wire.

If the above answer is acceptable, then the next question is:
What is the Norton equivalent of a circuit with a Thevenin voltage of 5 V and a Thevenin resistance of 10 ohms?

[Things2do]

1: What is the chemical formula of lodeston?
2: What is a electromagnet, and how does it work?

Answer (Click to Show Hidden Text)

1. Lodestone has the formula Fe[sub]3[/sub]O[sub]4[/sub] with one of the iron atoms being in the +2 state and the other 2 in the +3 oxidation state.
2. An electromagnet is a device that produces a magnetic field from an electric current. Without going into too much physics, electric current flowing through a wire creates a magnetic field around the wire in a direction that is consistent with the right-hand-rule. By winding the wire into a helix, you add together these smaller magnetic fields into a stronger magnetic field passing through the axis of the helix. This allows you to control the magnetic field by controlling the current you pass through the wire.

If the above answer is acceptable, then the next question is:
What is the Norton equivalent of a circuit with a Thevenin voltage of 5 V and a Thevenin resistance of 10 ohms?

Works for me.

What is the Norton equivalent of a circuit with a Thevenin voltage of 5 V and a Thevenin resistance of 10 ohms?

[UTF-8 U+6211 U+662F]

What is the Norton equivalent of a circuit with a Thevenin voltage of 5 V and a Thevenin resistance of 10 ohms?

Click to Show Answer

10 ohms, 0.5 A

[mdv2o5]

What is the Norton equivalent of a circuit with a Thevenin voltage of 5 V and a Thevenin resistance of 10 ohms?

Click to Show Answer

10 ohms, 0.5 A

Looks good to me! Your turn.