Generators and Voltage-Current Relationship

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Questions and Answers

In the context of a generator's behavior, what does the constant 'b' physically represent?

The internal resistance of the generator.
The terminal voltage of the generator under load.
The electromotive force (emf) of the generator. (correct)
The current flowing through the generator.

Does the electromotive force (E) of a generator typically remain constant when the current (I) changes?

No, the emf (E) decreases inversely with the current (I).
The emf (E) fluctuates randomly with changes in current (I).
No, the emf (E) increases proportionally with the current (I).
Yes, the emf (E) is independent of the current (I). (correct)

If you measure the terminal voltage of two different non-load batteries, one marked 1.5V and another marked 9V, would their electromotive force (E) be the same?

Yes, all batteries will have the same emf (E).
Yes, only when they are connected in series.
No, each battery's emf (E) is a specific characteristic of that battery. (correct)
No, emf (E) depends on the environment temperature.

What does the term 'a' represent relative to a generator, and what are its SI units?

The internal resistance, measured in Ohms ($Ω$). (C) Signup and view all the answers

What is the general form of the voltage (U) across a generator with electromotive force (E) and internal resistance (r) in terms of the current (I)?

$U = E - rI$ (D) Signup and view all the answers

According to the experiment, what happens to the voltage (U) across the terminals of a generator as the current (I) it delivers increases?

The voltage (U) decreases as the current (I) increases. (B) Signup and view all the answers

What is represented by the U-I characteristic curve of a generator?

The variation of voltage (U) across the terminals as a function of current (I). (A) Signup and view all the answers

What two key parameters characterize a real-world generator?

Electromotive force (E) and internal resistance (r). (A) Signup and view all the answers

In the equation of the graph U = aI + b, what does the term 'b' represent?

The electromotive force (emf) of the generator. (C) Signup and view all the answers

What is the shape of the U-I characteristic curve typically for a real generator?

A downward sloping straight line. (C) Signup and view all the answers

If you plot the U-I characteristic curve, what would the slope of the straight line represents?

The internal resistance of the generator (with a negative sign). (D) Signup and view all the answers

In the experimental setup, why are lamps added in parallel when measuring the U-I characteristics of a generator?

To vary the current drawn from the generator. (C) Signup and view all the answers

In the equation U = aI + b, what are the correct SI units for the constant 'b'?

Volts (V). (B) Signup and view all the answers

Flashcards

What is Electromotive Force (EMF)?

Electromotive force (emf) is the voltage generated by a power source, like a battery or generator, when no current is flowing. It represents the maximum potential difference that the source can provide.

Does EMF vary with current?

No, the electromotive force (E) is constant and does not change with the current (I) flowing through the circuit. It's an intrinsic property of the generator.

Is EMF the same for all batteries?

The voltage across the terminals of a battery (like a 1.5V or 9V battery) represents its electromotive force (E). Different batteries have different EMF values.

Is EMF a Generator Characteristic?

Yes, EMF is a characteristic property of a generator, representing its ability to generate a potential difference. Just like a battery has a specific voltage, a generator has a specific EMF.