Physics II Exam 2
The direction of convention current is taken to be the direction that
positive charges would flow
The current in a 400 watt device was measured to be 200 mA. What is the internal resistance of the device?
10 k ohm
A camping lantern operating at 6 V draws 0.5 A of current. What is its resistance
12.0 Ω
In the following diagram, each resistor is 10 ohms. The voltage of the batteries is 15 V. 1. What is the equivalent resistance of the circuit in ohms? Round your answer to the nearest whole number and do not include units. 2. What is the total current in the circuit in amps? Report your answer to two places past the decimal. Include a 0 before the decimal if needed. (x.xx) 3. What is the potential difference across resistor 2? Answer as x.xx
Answer for blank # 1: 27.00 Answer for blank # 2: 0.56 Answer for blank # 3: 5.60
What is the power, in watts, in a electrical appliance that uses 110 V and has a current of 120 mA? Report your answer as xx.x and do not include units.
Answer: 13.2
Consider two copper wires. One has twice the length of the other. How do the resistivities of these two wires compare?
Both wires have the same resistivity.
When two or more resistors are connected in parallel to a battery,
all of the given answers
When two or more resistors are connected in series to a battery
all of the given answers
A coulomb per second is the same as
an ampere.
What is the name of the following piece of equipment?
bread board
The given circuit symbol represents
electrical potential
Four 15-Ω resistors are connected in series. What is the equivalent resistance?
60 Ω
The resistance of a wire is defined as
(current)/(voltage).
What is the total current of the circuit in the figure below if E = 20V ?
0.4 A
A 25-W soldering iron runs on 110 V. What is its resistance?
0.48 kΩ
What is 1 W equivalent to?
1 V∙A
Three resistors of 12, 6.0, and 6.0 Ω are connected in parallel. A 12-V battery is connected to the combination. What is the current through the 12.0-Ω resistor?
1.0 A
Question 25 2 / 2 points The following three appliances are connected to a 120-V circuit: 1200-W toaster, 650-W coffee pot, and 600-W microwave. If all were operated at the same time what total current would they draw?
20 A
A 10-A current flows into a series combination of a 2.0-Ω and a 4.0-Ω resistor. What is the voltage drop across the 2.0-Ω resistor?
20 V
A 6.0-Ω and a 12-Ω resistor are connected in parallel to a 36-V battery. What power is dissipated by the 6.0-Ω resistor?
220 W
Four identical resistors are connected in parallel to a battery. If the current of 12 A flows from the battery, how much current flows through any one of the resistors?
3 A
What current is flowing if 0.85 C of charge pass a point in 0.25 s?
3.4 A
A 3.0-Ω resistor is in series with a parallel combination of 2.0 Ω, 6.0 Ω, and 12 Ω. What is the equivalent resistance of this combination?
4.3 Ω
What potential difference is required to cause 250 mA to flow through a resistance of 200 Ω?
50 V
A 14-A current flows into a series combination of a 3.0-Ω and a 4.0-Ω resistor. What is the voltage drop across the 4.0-Ω resistor?
56 V
Two identical resistors are connected in series to a 12-V battery. What is the voltage across any one of the resistors?
6 V
The total amount of charge that passes through a wire's full cross section at any point per unit of time is referred to as
current
what happens to the voltage across the resistor R1 when the switch is closed? The voltage will
increase
The resistance of a wire is
proportional to its length and inversely proportional to its cross-sectional area.
If the voltage across a circuit of constant resistance is doubled, the power dissipated by that circuit will
quadruple
The resistivity of a wire depends on
the material out of which it is composed.
Consider two copper wires. One has twice the cross-sectional area of the other. How do the resistances of these two wires compare?
the thicker wire has half the resistance of the shorter wire.