Current, voltage, charge, energy and power. They are all measurements used in a circuit.
1-3. What are the missing words in this passage? |
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| The current in a circuit is the rate of flow of
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| The voltage can be though of as an electrical
which gives a measure of the energy transferred. |
| The electrical power transferred in a circuit is the
transferred per second. |
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4. The unit for current is the
- A. amp
- B. volt
- C. watt
- D. joule
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5. The unit for power is the
- A. amp
- B. volt
- C. watt
- D. joule
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6. Look at the formula for power on the right. The rearranged formula needed to calculate the current (I) is...
- A. I = P / V2
- B. I = V / P
- C. I = P / V
- D. I = P x V
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P = I x V |
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7. Look at the formula for power on the right. The rearranged formula needed to calculate energy tranferred is ....
- A. E = P / t2
- B. E = P x t
- C. E = t / P
- D. E = P / t
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P = E / t |
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8. If you push a metal bar quickly between 2 magnets it produces a voltage in the bar. What is this effect called?
- A. Induction
- B. Reduction
- C. Generation
- D. Production
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9. The diagram shows a coil turning in between two magnets to make a voltage to heat a resistor. What would happen if the coil was rotated faster?
- A. The resistor would stay the same temperature.
- B. The resistor would take more current but stay the same temperature.
- C. The voltage and temperture would increase
- D. The resistor would cool down.
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10. Which of these methods will not generate a voltage?
- A. Rotate a coil in a magnetic field
- B. Rotate a magnet inside a coil
- C. Move a magnet past a wire
- D. Move a wire past a coil
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11. A.C. generators are found in
- A. C.D. players
- B. Phone chargers
- C. Power stations
- D. Amplifiers
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12. To increase the voltage generated you change many factors. Which one of these will NOT work?
- A. Increase the strength of the magnets
- B. Use thinner wires
- C. Spin the coil faster
- D. Have more turns on the coil
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13. A.C. and D.C. are two types of electric current. Which of these pairs of descriptions is correct?
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A.C. |
D.C. |
| A |
current flows one way |
current changes direction |
| B |
current changes direction |
current flows one way |
| C |
current changes direction |
current varies in strength |
| D |
current varies in strength |
current changes direction |
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14. A non-renewable energy source is one that
- A. will run out
- B. can be regenerated
- C. will never run out
- D. can be replaced with solar power
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15. Which one of the following energy resources is renewable?
- A. Coal
- B. Nuclear power
- C. Natural gas
- D. Hydroelectric
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