Question 1 Part (a) Select all the correct statements about electric current. The electric current in a wire is a flow of electrons, while by convention we think of it as a flow of positive charges in the opposite direction. Question 2 The electric current flowing at a point along a conducting wire is the amount of charge flowing per unit time through the wire's cross-sectional area at that point. The flowing charges forming an electric current can be positive or negative charged particles. The electric current in a wire is a flow of positive charges. An electric current can flow in a wire in the absence of a potential difference along the wire. Part (b) Select all the correct statements. Ohm's law can be written in the form I = RAV. The resistance of a wire depends on the wire's resistivity, length, and cross-sectional area. All wires made of the same material at the same temperature have the same resistance. Ohm's law can be written in the form AV = IR. The resistance of a wire depends only on the resistivity of the wire's material. Part (a) As the temperature of a conductor is lowered, its resistance typically... (select the best choice) Ostays the same O decreases and then increases increases increases and then decreases Odecreases

13 A student is attempting to create a circuit that will generate the maximum amount of heat possible. All resistors have equivalent length, area, and shape. Resistance Materials Resistance Material (요) Aluminum 2.7 Germanium 1,500,000 Quartz 7,500,000,000 Silver 1.6 Which of the following would be most effective in generating heat? A Aluminum B Germanium C Quartz D Silver

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Pane 15. The resistance of the following resistor, fig. 2, is Green Blue Red Fig 2. a) 339 2 b) 5.6 k2 c) 560 2 d) 260 k2 16. 2A current passes through a resistor of 60 2 when a battery is connected across this resistor. The voltage across the resistor is a) 120V b) 220V c)15 V D) 30V