| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.11 |
| Score | 0% | 62% |
Which of the following will increase the magnetic field produced by the electric current in a wire?
wind the wire into a coil |
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wrap the wire around a ceramic core |
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construct the wire from conductive material |
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construct the wire from insulative material |
A moving electric current produces a magnetic field proportional to the amount of current flow. This magnetic field can be made stronger by winding the wire into a coil and further enhanced if done around an iron containing (ferrous) core.
The sum of the voltage drops across each resistor in a __________ circuit will equal the total voltage applied to the circuit.
series-parallel |
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series |
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parallel |
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closed |
A series circuit has only one path for current to flow. In a series circuit, current (I) is the same throughout the circuit and is equal to the total voltage (V) applied to the circuit divided by the total resistance (R) of the loads in the circuit. The sum of the voltage drops across each resistor in the circuit will equal the total voltage applied to the circuit.
This circuit component symbol represents a(n):
capacitor |
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transformer |
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AC source |
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DC source |
Direct current flows in only one direction in a circuit, from the negative terminal of the voltage source to the positive. A common source of direct current (DC) is a battery.
An amplifier is most similar in function to which of the following:
capacitor |
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step-down transformer |
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transistor |
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step-up transformer |
An amplifier is a device that takes a small input signal and creates a larger output signal. This makes it most similar to a step-up transformer which takes a smaller input voltage and creates a larger output voltage.
Why is an insulator a poor conductor of electricity?
an insulator is made of inorganic material |
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an insulator has few free electrons |
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an insulator has many free electrons |
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an insulator is made of organic material |
Insulators have valence shells that are more than half full of electrons and, as such, are tightly bound to the nucleus and difficult to move from one atom to another.