1. A large spool in an electrician's workshop has 75 m of insulation coated wire coiled around it. When the electrician connects a battery to the ends of the spooled wire, the resulting current is 1.1 A. Some weeks later, after cutting off various lengths of wire for use in repairs, the electrician finds that the spooled wire carries a 2.9-A current when the same battery is connected to it. What is the length of wire remaining on the spool? m

8 - The figure in the attachment represents a section a circular conductor of nonuniform diameter carrying a current of 6 A. radius of cross section A1 is 0.5 cm. What is the magnitude of the current density across A,? Ag A1 Figure P27.8 a) O 50,64 kA/m? b) O 56,4 kA/m2 c) O 76,4 kA/m2 d) O 76 A/m² O 56,4 A/m?

A long, cylindrical wire with a length of 1.5 m and a cross-sectional area of 5.0 mm2 carries a steady current of 5.0 A. If the number density of free electron carriers in the wire is 8.0 x 1028 e- ' s/m3, what is the drift velocity of the free electrons that carry the current?   a. 6.5 x 10-7 m/s   b. 7.8 x 10-7 m/s   c. 4.2 x 10-7 m/s   d. 9.7 x 10-7 m/s   e. 2.1 x 10-6 m/s

QUESTION 16 A lightbulb in a home is emitting light at a rate of 120 watts. If the resistance of the light bulb is 15.0 Q, what is the current passing through the bulb? а. 2.10 A b. 4.43 A С. 2.83 А d. 1.75 A Ое. 3.56A

The current in a wire at time t is given by the expression I(t) = (2.4 A) e−t/(2.3 µs), where t is in µs. a. Graph I vs t for the interval 0 ≤ t ≤ 10 μs. b. Find an expression for the total amount of charge that has entered the wire at time t if Q(0) = 0 C. c. Graph the total amount of charge that has entered the wire as a function of time for the same interval as in part a.

9 What is the total electrical energy used by a 9 V battery when connected to a 15 N resistor for 25 seconds? A 5.4 J B 41.7 J C 135 J D 30,375 J

Taking R = 1.20 kΩ and ℰ = 470 V in the figure shown below, determine the magnitude and direction of the current in the horizontal wire between a and e. magnitude ?mA

Taking R = 1.50 kΩ and ε = 150 V in the figure shown below, determine the magnitude and direction of the current in the horizontal wire between a and e. 17.5 mA, from e to a19.9 mA, from a to e    18.0 mA, from e to a18.9 mA, from a to e18.0 mA, from a to e19.9 mA, from e to a

1. A flashlight bulb carries a current of 0.38 A for 98 s. How much charge flows through the bulb in this time? How many electrons? Chap 21_#1 2. When a potential difference of 12 V is applied to a given wire, it conducts 0.45 A of current. What is the resistance of the wire? Cha 21_#10 3. When a potential difference of 12 V is applied to a wire 6.9 m long and 0.33 mm in diameter, the result is an electric current of 2.1 A. What is the resistivity of the wire? Chap 21_#18 4. A 65-W lightbulb operates on a potential difference of 95 V. Find (a) the current in the bulb and (b) the resistance of the bulb. (c) If this bulb is replaced with one whose resistance is half the value found in part (b), is its power rating greater than or less than 65 W? By what factor? Chap 21 #30 5. A 99-0 resistor has a current of 0.82 A and is connected in series with a 110@0 resistor. What is the emf of the battery to which the resistors are connected? Chap 21 #44 6. Find the equivalent resistance between…

Under the influence of a constant E field of 700.0 N/C; 4.53* 1016 electrons pass through a 5.00 cm piece of wire in 5.00 seconds. a) What is the potential difference across the wire? b) What is the average current during this time period? c) What is the average power during this time? d) What is the effective resistance of the wire?