Download Practice Test 2

Practice Test 2
Name: __________
SP212
Instructor: Jacob Cohen
Instructions:
1. You must show all
multiple choice problems.
2. You may use a calculator.
your work in order to gain full credit on the non-
Test:
1. In the figure below, the battery has a potential difference of 20V. The capacitors have
been charged up and current is no longer flowing in the circuit. a) Find the equivalent
capacitance of all the capacitors and b) the charge stored on that equivalent capacitance.
Find the potential and charge on c) capacitor 1 and d) capacitor 2. e) How much energy is
stored in capacitor 3? C1 = 3 µF, C2 = 2 mF, C3 = 4 µF.
2. a) Calculate the current through each ideal battery in the figure below. Assume the R1
= 1.0 Ω, R2 = 2.0 Ω, V1 = 2.0 V, and V2 = V3 = 4 V. b) Calculate Vb – Va. c) Calculate the
power dissipated in the resistor R2.
3. A rectangular coil of wire with 20 turns, 22 cm by 35 cm and carrying a current 1.40 A,
is oriented with the plane of its loop perpendicular to a uniform 1.50 T magnetic field, as
shown in the figure. a) Calculate the net force and the torque which the magnetic field
exerts on the coil. b) The coil of wire is rotated through a 30 angle about the axis
shown, the left side coming out of the plane of the figure and the right side going into the
plane. Calculate the net force on the coil and the net torque which the magnetic field now
exerts on the coil. c) Find the potential energy associated with the orientation of the loop
in part b).