闪卡自测
Define current.
所有闪卡
闪卡 1
问题
Define current.
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答案
Current is the rate of flow of electric charge.
闪卡 2
问题
Define 1 amp.
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答案
1 amp is equivalent to a charge of 1 coulomb flowing in 1 second, or 1 A = 1 C/s.
闪卡 3
问题
What is the equation linking charge, current, and time?
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答案
The equation linking charge, current, and time is: Where:
闪卡 4
问题
What is the purpose of an ammeter?
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答案
The purpose of an ammeter is to measure the current at a point in a circuit.
闪卡 5
问题
True or False? Ammeters should be connected in series with components.
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答案
True. Ammeters should be connected in series with components to measure current.
闪卡 6
问题
True or False? Conventional current flows from the negative terminal to the positive terminal of a cell.
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答案
False. Conventional current is the flow of positive charge around a circuit, from the positive terminal to the negative terminal.
闪卡 7
问题
What is the difference between electron flow and conventional current?
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答案
Conventional current defines current as the flow of positive charge. Electrons flow from the negative terminal to the positive terminal of the cell. This is the opposite direction to conventional current.
闪卡 8
问题
True or False? The current in a solid metallic conductor is a flow of positively charged protons.
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答案
False. The current in a solid metallic conductor is a flow of negatively charged electrons.
闪卡 9
问题
Define voltage.
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答案
Voltage is the energy transferred per unit charge passing between two points.
闪卡 10
问题
Define 1 volt.
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答案
1 volt is equivalent to the transfer of 1 joule of energy by 1 coulomb of charge, or 1 V = 1 J/C.
闪卡 11
问题
What is the equation linking energy, charge and voltage?
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答案
The equation linking energy, charge and voltage is: Where:
闪卡 12
问题
True or False? Voltage is measured in amperes.
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答案
False. Voltage is measured in volts (V).
闪卡 13
问题
What is the purpose of a voltmeter?
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答案
The purpose of a voltmeter is to measure the voltage between two points in a circuit.
闪卡 14
问题
True or False? Voltmeters should be connected in series with components.
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答案
False. Voltmeters should be connected in parallel with components.
闪卡 15
问题
How much energy is gained by a coulomb of electrons flowing through a 12 V cell?
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答案
A coulomb of electrons flowing through a 12 V cell gains 12 J of energy.
闪卡 16
问题
True or False? When electrons flow in a circuit, they lose energy.
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答案
True. As electrons flow through a circuit, they lose energy as it is transferred to the wires and components.
闪卡 17
问题
Define resistance.
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答案
Resistance is the opposition to the flow of electric current by a component.
闪卡 18
问题
Define 1 ohm.
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答案
1 ohm is equivalent to a voltage across a component of 1 V which produces a current of 1 A through it.
闪卡 19
问题
What is the equation linking voltage, current and resistance?
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答案
The equation linking voltage, current and resistance is: Where:
闪卡 20
问题
True or False? Resistance is measured in volts.
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答案
False. Resistance is measured in ohms, represented by the Greek symbol omega (Ω).
闪卡 21
问题
True or False? The resistance of wires in a circuit can be assumed to be zero.
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答案
True. Wires can be assumed to have zero resistance.
闪卡 22
问题
True or False? The current flowing through a conductor of fixed resistance is directly proportional to the potential difference across it.
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答案
True. The current flowing through a conductor of fixed resistance is directly proportional to the potential difference across it.
闪卡 23
问题
True or False? The higher the resistance of a component, the higher the current that can flow through it when the voltage is constant.
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答案
False. The higher the resistance of a component, the lower the current that can flow through it when the voltage is constant.