Physics Final Part II (Second Semester)
2.4 x 10 ^2Ω ; 60 W
A lamp draws a current of 0.50 A when it is connected to a 120 V source. What is the resistance of the lamp and what is the power consumption of the lamp?
4.45 A
A parallel circuit has two branch currents: 3.45 and 1.00 A. What is the current in the energy source?
2.32 N
Two charged bodies exert a force of 0.145 N on each other. If they are moved so that they are 1/4 as far apart, what force is exerted?
50 W bulb
Two light bulb work on a 120 V circuit. One is 50 W and the other is 100 W. Which bulb has a higher resistance?
each new resistor provides an additional path for the current
Why does the equivalent resistance decrease as more resistors are added to a parallel circuit?
no effect
What is the effect on the current in a circuit if both the voltage and the resistance are both doubled?
appliance in parallel can be run independently of one another
Why is the household wiring constructed in parallel instead of in a series?
3.15 A
A 15.0Ω resistor and a 20.0Ω resistor are connected in parallel. A 5.00Ω resistor is connected in series with this parallel arrangement. The resistors are connected across a 1.00 x 10^2 V battery. What is the current flowing through the 20.0Ω resistor?
8.0 A
A 15Ω electric heater operates on a 120 V outlet. What is the current through the heater?
a: 55Ω b. 2.2 A c. 48 V, 72 V d. 1.20 x 10^2 V
A 22Ω resistor and a 33Ω resistor are connected in series and placed across a 120V potential difference. (a) What is the equivalent resistance of the circuit? (b) What is the current in the circuit? (c) What is the voltage drop across each resistor? (d) What is the voltage drop across the two resistors together?
0.60 A; 2.1x10^2Ω
A 75 W lamp is connected to a 125 V. What is the current through the lamp and what is the resistance of the lamp?
2.00 uF
A capacitor that is connected to a 45.0 V source contains 90.0 uC of charge. What is the capacitance?
1.5 x 10^4
A sensor uses 2.0 x 10 ^-4 A of current when it is operated by a 3.0 V battery. What is the resistance of the sensor circuit?
0.36 A
An automobile panel lamp with a resistance of 33Ω is placed across a 12 V battery. What is the current through the circuit?
6.8 uF capacitor; 1.6 x 10^-4
Both a 3.3 uF and a 6.8 uF capacitor are connected across a 24 V electric potential difference. Which has a greater charge? What is it?
12 kΩ; 0.40 kΩ
Calculate the equivalent resistance of the following resistors if they are connected in series: 680Ω, 1.1kΩ, 10kΩ. What would the equivalent resistance be if they were connected in parallel?
A: there will be no current B: the current will remain the same
Circuit A contains three 60Ω resistors in series. Circuit B contains three 60Ω resistors in parallel. How does the current in the 2nd 60Ω resistor of each circuit change if a switch cuts off the current to the first 60Ω resistor?
current has to be the same at both points
Compare the amount of current entering a junction in a parallel circuit with the current that leaves the junction
like charges repel and opposite charges attract
Describe the force when the charges are alike and the force when the charges are opposite?
differences between electric potential energy and the electric potential difference
EPE: changes when work is done to move a charge in an electric field; depends on the amount of charge involved EPD: work done per unit charge to move a charge in an electric field; it is independent of charge that is moved
directly related
How are electric force and charge related?
inversely proportional
How are electric force and distance related?
have the same magnitude (1.6 x 10^-19); have opposite signs
How does the charge of an electron differ from the charge of a proton? How are they similar?
it depends on the magnitude and sign of the test charge
How does the electric field at the test charge differ from the force acting on it?
greater concentration of field lines = greater electric field
How is the strength of an electric field indicated with electric field lines?
5.6 x 10 ^-6 C
How much charge is stored on a 0.47 uF capacitor when a potential difference of 12 V is applied to it?
1/9 as great
How would the force change if the distance between two charges were tripled?
resistance is doubled = current is halved
If the voltage across a circuit is kept constant and the resistance is doubled, what effect does this have on the circuit's current?
equivalent resistance will be less than that of any of the resistors
Several resistors with different values are connected in parallel. How do the values of the individual resistors compare to the equivalent resistance?
5.00Ω, 6.00 A, 2.00 A
Three 15.0Ω resistors are connected in parallel and placed across a 30.0 V battery. Find the equivalent resistance for the circuit, the equivalent current, and the current through each branch of the circuit.
60Ω; 2 A
Three 20Ω resistors are connected in series across 120 V generator. What is the equivalent resistance of the circuit? What is the current in the circuit?
40.0 V
Three resistors of 1.00 x 10^2Ω, 3.90kV, and 1.00kΩ are connected in series across a 2.00 x 102 V battery. What is the voltage drop across the resistor of value 1.00kΩ ?
away from positive; toward the negative
What are the directions of the electric field lines for a positive charge?
small and positive charge
What are the two properties that a test charge must have?
nothing, the force on the test charge would also be halved
What happens to the strength of an electric filed when the charge on the test charge is halved?
difference in equivalent resistance between three 60Ω resistors connected in a series then the same three resistors connected in parallel
current is opposed by each resistor in turn; total resistance is the sum of the resistors; parallel circuit, each resistance provides an additional path for the current; RESULT: a decrease in the total resistance
increase voltage or decrease resistance
describe two ways to increase the current in a circuit
