Think you’ve got your head wrapped around Electricity and Magnetism? Put your knowledge to
the test. Good luck — the Stickman is counting on you!
Q. Which of the following combinations of resistors will drain energy from a battery the fastest?
50 Ω and 50 Ω in parallel
100 Ω and 50 Ω in parallel
200 Ω and 100 Ω in parallel
75 Ω and 10 Ω in series
50 Ω and 50 Ω in series
Q. What is the current through R1 ? Every resistor has a resistance of 100 Ω.
12 mA
24 mA
48 mA
72 mA
180 mA
Q. A thermocouple is a device that uses two welded together pieces of metal to create a voltage when exposed to a temperature change. A chromel-alumel thermocouple will produce a voltage of about 4 mV for every 100° of temperature difference it sees. In a room-temperature kitchen (20°), what current will be produced by a meat thermometer made of a thermocouple with an internal resistance of 10 mΩ when it's plunged into a 90° roasted chicken?
2.8 mA
3.6 mA
280 mA
360 mA
28.0 A
Q. A parallel plate capacitor is attached to a 7.2 V battery for several minutes, then disconnected. The distance between the plates of the capacitor is then halved and a wire is connected from one end to the other. What is the initial voltage seen on the wire immediately after the capacitor is reconnected?
1.8 V
3.6 V
7.2 V
14.4 V
28.8 V
Q. Two inductors, one with L1 = 100 mH and one with L2 = 200 mH, are connected in series. L 1 has an internal resistance of 10 Ω, and L2 has an internal resistance of 20 Ω. When a voltage is applied to the circuit, what is the ratio of energy stored in L1 versus L2?
1/4
1/2
1/1
2/1
4/1
Q. Two batteries labeled at 12 V—but with an internal resistance of 8 Ω—are connected in series. They are then both connected to a lamp consisting of three 100 Ω light bulbs wired in parallel. What is the current through each bulb?
75.9 mA
162 mA
243 mA
486 mA
581 mA
Q. Batteries are often measures in amp-hours, a unit of charge where 1 Ah = 3600 C. This is, essentially, a way to measure how long a battery can provide a given current. If a 6.4 V battery rated at 700 mAh is attached to five 50 Ω light bulbs in series, about how long can the battery keep the lights on for?
1 hr
5 hrs
11 hrs
18 hrs
27 hrs
Q. How much energy can be stored in two parallel plate capacitors consisting of 0.01 m2 metal plates separated by 1 μm when they're attached in parallel to a 4 V battery?
0.088 μ J
0.35 μ J
0.71 μ J
1.42 μ J
2.83 μ J
Q. What is the equivalent resistance of this six-resistor network? Every resistor is 1 kΩ.
167 Ω
667 Ω
1333 Ω
1625 Ω
6000 Ω
Q. When a battery is attached to the resistor network in the previous question, what percent of the overall power dissipated is lost in R1 ?
1%
4%
31%
40%
62%