Physics Current Electricity Level: University
ConductanceA silver wire of diameter 1.0 mm carries a current of 150 mA. The density of conduction electrons in silver is 5.8 x 10^28 m^-3. How long (on average) does it take for a conduction electron to move 1.0 cm along the wire?
Physics Current Electricity Level: University
The starter motor in a car draws 220.0 A of current from the 12.0 V battery for 1.20s . Determine how much charge is pumped by the battery and how much electrical energy is supplied to the battery.
Physics Current Electricity Level: University
Two electrodes are placed in a calcium chloride solution and a potential difference is maintained between them. If 3.8 x 10^16 Ca^2+ and 6.2 x 10^16 Cl ions per second move in opposite directions through an imaginary area between the electrodes what is the current in the solution?
Physics Current Electricity Level: University
Heating effect of currentNichrome wire is used in some in some radiative heaters. (a) Find the resistance needed if the average power output is to be 1.00 kw utilizing 120Vac. (b) What length of nichrome wire having a cross section area of 5.00 mm^2 is needed if the operating temp is 500 deg C. (c) What power will it draw when first turned on?
Physics Current Electricity Level: University
Heating effect of currentNichrome wire is used in some radiative heaters. (a) Find the resistance needed if the average power output is to be 1.00 kw utilizing 120 VAC. (b) What length of nichrome wire having a cross section area of 5.00mm^2 is needed if the operating temp is 500 deg C. (c) What power will it draw when first turned on ?
Physics Current Electricity Level: University
A resistor made of Nichrome wire is used in an application where its resistance cannot change more than 1.00% from its value at 20.0 deg C. over what temp range can it be used? (nichrome resistivity = 100* 10^-8)
Physics Current Electricity Level: University
Find the voltage drop in an extension card having a 0.0600 OHM resistance and through which 5.00 Amp is flowing. (b) A chepaer cord utilizes a thinner wire and has a resistance of 0.300 ohm what is the voltage drop in it when 5.00 Amp flows
Physics Current Electricity Level: University
Which one of the following situations results in a conventional electric current that flows westward?a. A bean of protons moves eastward.
b. An electric dipole moves westward.
c. A beam of electrons moves westward.
d. Abeam of electrons moves eastward.
e. A beam of neutral atoms moves westward.
Physics Current Electricity Level: University
Heating effect of currentThe current through a certain heater wire is found to be fairly independent of its temperrature. If the current through the heater wire is doubled, the amount of energy delivered by the heater in a given time interval will
(a) Increase by a factor of two.
(b) Decrease by a factor of two
(c)Increase by a factor of four
(d)Decrease by a factor of four
(e) Increase by a factor of eight
Physics Current Electricity Level: High School
Dc circuits
An inductor and a resistor are connected with a double pole switch to a battery as shown in the figure .The switch has been in position b for a long period of time . If the switch is thrown from position b to position a (connecting the battery) , how much time elapses current reaches 219 mA ? Answer in units of ms .
a) What is the maximum current in the inductor a long time after the switch is in position a ?
b) The switch has brushes within so that the switch can be thrown from a to b without internal sparking . Now the switch is smoothly thrown from a to b , shorting the inductor and resistor . How much time elapses before the current falls to 92 mA ?
Question Diagram
Physics Current Electricity Level: High School
Three 40 ohm light bulbs and three 70 ohm light bulbs are connected in series . What is the total resistance of the circuit ?
Physics Current Electricity Level: High School
Two 120 ohm resisters are connected in parallel to a 24.0 V battery . What is the equivalent resistance for the circuit ?
Physics Current Electricity Level: High School
Two 120 ohm resisters are connected in parallel to a 24.0 V battery . What is the equivalent resistance for the circuit ?
Physics Current Electricity Level: High School
Heating effect of current
One light bulb is marked “15 W 120 V” and another “60 W 120 V” . This means that each transforms this amount of electrical energy into light and heat per second when plugged into a constant 120-V potential difference . (You may assume 3 significant digits for the markings) .a) Find the resistance of each bulb . When they are connected to a 120 V power supply which bulb is brighter ?
b) How longs does it take for 1.00 C to pass through the dim bulb ? How is this charge different upon its exit versus its entry into the bulb ?
c) How long does it take the dim bulb to dissipate 1.00 J of energy ?
d) Find the cost of running the dim bulb continuously for 30.0 days if the electric company sells its product at $0.800 per kilowatt-hour (kWh) .
e) What physics quantity does the electric company sell ? What is the price for one SI unit of this quantity ?
f) Assume you can buy gasoline at $2.00 gallon and each gallon contains 114000 Btu . What is the ratio of the cost energy from the electrical power company over the cost of energy from the gas pump ?
Physics Current Electricity Level: High School
Ohm's lawA 21.0 W energy efficient fluorescent lamp is designed to produce the same illumination as a standard 50.0 W lamp.
a) How much energy does this lamp save during 80.0 h of use?> answer in units of J.
b) If electric energy does cost $0.80/kW-h, how much money is saved in 80.00 h? Answer in units of dollars.
