Question

reinforcement electric current
directions: circle the term in parentheses that makes each statement true.

1. a negatively charged object has (more, fewer) electrons than an object that is neutral.
2. electrons flow from areas of (higher, lower) voltage to areas of (higher, lower) voltage.
3. voltage difference is measured in (amperes, volts).
4. electrons passing through a lamp (gain, lose) some voltage as they light the lamp.
5. voltage (varies, is the same) in all parts of a series circuit.
6. the current in a circuit is measured in (volts, amperes).
7. current is almost always the flow of (electrons, protons)
8. when a dry cell is connected in a series, the flow of electrons moves from the (positive, negative) terminal to the (positive, negative) terminal.
9. in a dry - cell, the carbon rod releases electrons and becomes the (positive, negative) terminal.
10. the voltage difference between the two holes in a wall socket is (12 volts, 120 volts).
11. a car battery is an example of a (dry, wet) cell.
12. resistance is measured in (ohms, volts).
13. copper has a (higher, lower) resistance to electron flow than tungsten.
14. according to ohms law, (i = v/r, v = i/r)
15. the symbol for ohm is (ω, °).
16. in the equation i = v/r, i is expressed in (ohms, amperes).
17. in the equation i = v/r, v is expressed in (volts, ohms).
18. the (+, -) terminal of a dry cell identifies the location of the carbon rod.
19. a wire with a resistance of 3ω has a (greater, lesser) resistance to electron flow than a wire with a resistance of 5ω.
20. if two copper wires are the same length, but different thicknesses, the (thinner, thicker) wire has greater resistance.

Explanation:

1. A negatively - charged object gains electrons, so it has more electrons than a neutral object.
2. Electrons flow from areas of higher voltage to areas of lower voltage.
3. Voltage difference is measured in volts. Amperes measure current.
4. As electrons pass through a lamp and do work (light the lamp), they lose some voltage.
5. In a series circuit, voltage varies across different components according to their resistance.
6. Current in a circuit is measured in amperes. Volts measure voltage.
7. Current is usually the flow of electrons as they are the charge - carriers in most conductors.
8. In a dry - cell series connection, electrons move from the negative terminal to the positive terminal.
9. In a dry cell, the carbon rod is the positive terminal as it releases electrons.
10. The voltage difference between the two holes in a standard wall socket in the US is 120 volts.
11. A car battery is a wet cell as it contains liquid electrolyte.
12. Resistance is measured in ohms. Volts measure voltage.
13. Copper has a lower resistance to electron flow than tungsten, which is why copper is a better conductor.
14. Ohm's law is \(I = V/R\), where \(I\) is current, \(V\) is voltage, and \(R\) is resistance.
15. The symbol for ohm is \(\Omega\). The degree symbol (\(^{\circ}\)) is for angles or temperature.
16. In \(I = V/R\), \(I\) (current) is expressed in amperes.
17. In \(I = V/R\), \(V\) (voltage) is expressed in volts.
18. The positive (\(+\)) terminal of a dry cell identifies the location of the carbon rod.
19. A wire with a resistance of \(3\Omega\) has a lesser resistance to electron flow than a wire with a resistance of \(5\Omega\) as resistance values are directly comparable.
20. For two copper wires of the same length but different thicknesses, the thinner wire has greater resistance as resistance is inversely proportional to the cross - sectional area.

Answer:

1. more
2. higher, lower
3. volts
4. lose
5. varies
6. amperes
7. electrons
8. negative, positive
9. positive
10. 120 volts
11. wet
12. ohms
13. lower
14. \(I = V/R\)
15. \(\Omega\)
16. amperes
17. volts
18. \(+\)
19. lesser
20. thinner