Edition By Douglas C. Giancoli Test Bank All Chapters, 100 Original Verified,

1) Internal battery resistance: In the figure, when the terminal voltage V ab of the battery is equal to 20 V, how much current passes through the battery, including its direction? 1) A) 6 A, from a to b B) 5 A, from a to b C) 4 A, from b to a D) 5 A, from b to a E) 4 A, from a to b 2) Internal battery resistance: The emf and the internal resistance of a battery are as shown in the figure. When the terminal voltage V ab is equal to 17.4 V, what is the current through the battery, including its direction? 2) A) 6.8 A, from b to a B) 8.7 A, from b to a C) 16 A, from b to a D) 6.8 A, from a to b E) 8.7 A, from a to b 3) Current density: A proton beam that carries a total current of 1.3 mA has 10.0 mm diameter. The current density in the proton beam increases linearly with distance from the center. This is expressed mathematically as J ( r ) = J 0 ( r/R ), where R is the radius of the beam and J 0 is the current density at the edge. Determine the value of J 0 . 3) A) 6.2 A/ m 2 B) 17 A/ m 2 C) 25 A/ m 2 D) 12 A/ m 2 1 Physics for Scientists & Engineers with Modern Physics (Volume 2) 5e (Global Edition) By Douglas C. Giancoli (Test Bank All Chapters, 100% Original Verified, A+ Grade) (Chapters 21-35) Answers At The End Of Each Chapter M ULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.Chapter 21 1 / 4

4) Current: The figure shows a 2.0-cm diameter roller that turns at 90 rpm. A 4.0-cm wide plastic film is being wrapped onto the roller, and this plastic carries an excess electric charge having a uniform surface charge density of 5.0 nC/cm 2 . What is the current of the moving film? 4) A) 11 A B) 23 A C) 190 nA D) 30 nA 5) Basics of ac circuits: A 500-W device is connected to a 120-V ac power source. What peak current flows through this device? 5) A) 150 A B) 120 A C) 4.2 A D) 170 A E) 5.9 A 6) Power: The voltage and power ratings of a particular light bulb, which are its normal operating values, are 110 V and 60 W. Assume the resistance of the filament of the bulb is constant and is independent of operating conditions. If the light bulb is operated with a current that is 50% of the current rating of the bulb, what is the actual power drawn by the bulb? 6) A) 15 W B) 10 W C) 20 W D) 30 W E) 25 W 7) Power: The resistivity of gold is 2.44 × 10 -8 Â m at room temperature. A gold wire that is 1.8 mm in diameter and 11 cm long carries a current of 170 mA. How much power is dissipated in the wire? 7) A) 0.013 mW B) 0.030 mW C) 0.0076 mW D) 0.025 mW E) 0.019 mW 8) Drift velocity: A silver wire has a cross sectional area A = 2.0 mm 2 . A total of 9.4 × 10 18 electrons pass through the wire in 3.0 s. The conduction electron density in silver is 5.8 × 10 28 electrons/m 3 and e = 1.60 × 10 -19 C. What is the drift velocity of these electrons? 8) A) 5.2 × 10 -5 m/s B) 7.4 × 10 -5 m/s C) 2.7 × 10 -5 m/s D) 1.1 × 10 -5 m/s E) 9.1 × 10 -5 m/s 2 2 / 4

9) Current density: If a current of 2.4 A is flowing in a cylindrical wire of diameter 2.0 mm, what is the average current density in this wire? 9) A) 21 × 10 -6 A/m 2 B) 1.9 × 10 5 A/m 2 C) 3.6 × 10 5 A/m 2 D) 7.6 × 10 5 A/m 2 E) 5.2 × 10 -6 A/m 2 10) Power: A certain electric furnace consumes 24 kW when it is connected to a 240-V line. What is the resistance of the furnace? 10) A) 1.0 k B) 100 C) 2.4 D) 0.42 E) 10 11) Current density: A certain fuse "blows" if the current in it exceeds 1.0 A, at which instant the fuse melts with a current density of 620 A/cm 2 . What is the diameter of the wire in the fuse? 11) A) 0.45 mm B) 0.91 mm C) 0.68 mm D) 0.63 mm 12) Power: A 1500-W heater is connected to a 120-V line. How much heat energy does it produce in 2.0 hours? 12) A) 11 MJ B) 1.5 kJ C) 0.18 MJ D) 18 MJ E) 3.0 kJ 13) Ohm's law: Two cables of the same length are made of the same material, except that one cable has twice the diameter of the other cable. When the same potential difference is maintained across both cables, which of the following statements are true? (There may be more than one correct choice.) 13) A) The current in the thin cable is twice as great as the current in the thick cable. B) Both cables carry the same current density. C) The current in the thin cable is four times as great as the current in the thick cable. D) The electrons have the same drift velocity in both cables. E) The same current flows through both cables. 14) Internal battery resistance: The emf and the internal resistance of a battery are shown in the figure. If a current of 7.8 A is established through the battery from b to a , what is the terminal voltage V ab of the battery? 14) A) -80 V B) -30 V C) 80 V D) zero E) 30 V 3 3 / 4

15) Ohm's law: When a voltage difference is applied to a piece of metal wire, a 5.0 -mA current flows through it. If this metal wire is now replaced with a silver wire having twice the diameter of the original wire, how much current will flow through the silver wire? The lengths of both wires are the same, and the voltage difference remains unchanged. (The resistivity of the original metal is 1.68 × 10 -8 Â m , and the resistivity of silver is 1.59 × 10 -8 Â m .) 15) A) 19 mA B) 5.3 mA C) 11 mA D) 21 mA 16) Current: In an electroplating process, copper (ionic charge +2 e , atomic weight 63.6 g/mol) is deposited using a current of 10.0 A. What mass of copper is deposited in 10.0 minutes? Avogadro's number is 6.022 × 10 23 molecules/mol and e = 1.60 × 10 -19 C. 16) A) 0.99 g B) 2.52 g C) 1.52 g D) 3.96 g E) 1.98 g 17) Power: A light bulb is connected to a 110-V source. What is the resistance of this bulb if it is a 100-W bulb? 17) A) 6.0 m B) 120 C) 240 D) 8.0 m E) 100 18) Power: A 110-V hair dryer is rated at 1200 W. What current will it draw when operating from a 110-V electrical outlet? 18) A) 14 A B) 5.0 A C) 90 mA D) 1.0 A E) 11 A 19) Power: The voltage and power ratings of a particular light bulb, which are its normal operating values, are 110 V and 60 W. Assume the resistance of the filament of the bulb is constant and is independent of operating conditions. If the light bulb is operated at a reduced voltage and the power drawn by the bulb is 36 W, what is the operating voltage of the bulb? 19) A) 85 V B) 66 V C) 78 V D) 72 V E) 90 V 20) Resistivity: What length of a certain metal wire of diameter 0.15 mm is needed for the wire to have a resistance of 15 ? The resistivity of this metal is 1.68 × 10 -8 Â m. 20) A) 1.6 m B) 16 cm C) 16 m D) 16 mm E) 160 m 21) Electric field in a wire: A narrow copper wire of length L and radius b is attached to a wide copper wire of length L and radius 2 b , forming one long wire of length 2 L . This long wire is attached to a battery, and a current is flowing through it. If the electric field in the narrow wire is E , the electric field in the wide wire is 21) A) 4 E . B) E /2. C) E . D) E /4 . E) 2 E . 4

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