WorksheetsAP-EM Practice
Total questions: 10
Worksheet time: 5mins
A 7.2 mH inductor is connected to a current source. What is the magnitude of the voltage in
the inductor at time 𝑡 = 3.0 𝑠 if the current is 𝐼(𝑡) = 5.0 + 7.0𝑡 − 2.0𝑡2
36 mV
22 mV
14 mV
39 mV
A 10-turn ideal solenoid has an inductance of 4.0 mH. To generate an emf of 2.0 V the current
should change at a rate of:
300 A/s
250 A/s
500 A/s
50 A/s
Which of the following has the largest inductance?
A solenoid of radius 2 cm, length 5 cm, and with 100 turns of wire per centimeter
A solenoid of radius 2 cm, length 2 cm, and with 100 turns of wire per centimeter
A solenoid of radius 3 cm, length 1 cm, and with 100 turns of wire per centimeter
A solenoid of radius 1 cm, length 5 cm, and with 100 turns of wire per centimeter
A long solenoid of length 2.0 𝑚 and 𝑛 = 300 𝑡𝑢𝑟𝑛𝑠/𝑚 carries a current of 4.0 𝐴. It stores an
energy of 3.4 𝐽. What is the cross-sectional area of the solenoid?
1.9 𝑚2
1.7 𝑚2
0.7 𝑚2
2.7 𝑚2
An emf of 10 V is applied to a coil having a resistance of 0.50 Ω. If it takes 0.55 s for the current to reach one half of its maximum value, what is the inductance of the coil?
397 mH
312 mH
379 mH
127 mH
What inductance should you put in series with a 100 Ω resistor to give a time constant of 2.2 ms?
220 mH
22 mH
0.22 mH
220 H
An 8.0 mH inductor and a 2.0 Ω resistor are wired in series to a 20-V ideal battery. A switch in the circuit is closed at time t = 0, at which time the current is zero. After a long time the current in the resistor and the current in the inductor are:
0 A, 0 A
10 A, 10 A
2.5 A, 2.5 A
10 A, 2.5 A
A 2.7 mH inductor is current to a current source. How much energy is stored in its magnetic field at time time 𝑡 = 3.0 𝑠 if the current is 𝐼(𝑡) = 2.0 + 9.0𝑡 − 4.0𝑡2?
0.0095 𝐽
0.041 𝐽
0.066 𝐽
0.13
In the circuit below, a fully charged capacitor with a capacitance C = 25 μF and charge Q = 4 μC
is connected to an inductor L = 10 mH.
37. What is the current in the circuit at the instant when the switch is closed?
0 A
1 A
5 A
10 A
Energy is stored in the magnetic field of an inductor. If the original amount of energy stored is 𝑈L how much energy will be stored if the current is reduced to half and the inductor is
replaced with one that has twice the inductance?
𝑈L/4
𝑈L/2
𝑈L
2𝑈L
