| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.36 |
| Score | 0% | 67% |
The watt is a unit of measurement for:
energy |
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resistance |
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power |
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frequency |
Electrical power is measured in watts (W) and is calculated by multiplying the voltage (V) applied to a circuit by the resulting current (I) that flows in the circuit: P = IV. In addition to measuring production capacity, power also measures the rate of energy consumption and many loads are rated for their consumption capacity. For example, a 60W lightbulb utilizes 60W of energy to produce the equivalent of 60W of heat and light energy.
| 1045 V | |
| 475 V | |
| 953 V | |
| 950 V |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
V = \( I \times R \) = \( 9.5 \times 100 \) = 950 V
Why is an insulator a poor conductor of electricity?
an insulator is made of organic material |
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an insulator has many free electrons |
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an insulator is made of inorganic material |
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an insulator has few free electrons |
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.
This circuit component symbol represents a(n):
resistor |
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transformer |
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inductor |
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capacitor |
An inductor is coiled wire that stores electric energy in the form of magnetic energy and resists changes in the electric current flowing through it. If current is increasing, the inductor produces a voltage that slows the increase and, if current is decreasing, the magnetic energy in the coil opposes the decrease to keep the current flowing longer. In contrast to capacitors, inductors allow DC to pass easily but resist the flow of AC.
Inductance is a factor in which of the following?
an AC circuit |
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a DC circuit |
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determining energy stored by a capacitor |
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batteries connected in serial |
Inductance is a property of an AC circuit (or a component in an AC circuit) that quantifies resistance to changes in current. The current in an AC circuit is continuously changing and inductive reactance (the opposition to change) depends both on the inductance of the circuit or component and the rate at which the current is changing.