Capacitor 1 has parallel plates of length L and width W, plate separation d, and is filled with dielectric with constant K.Capacitor 2 has parallel plates of length 2L and width 2W, plate separation 2d, and is filled with dielectric with constant 2k. If a voltage V is applied to capacitor 1 and a voltage 2V is applied to capacitor 2, which capacitor stores more energy and by what factor?
a. Capacitor 2 by a factor of 8
b. Capacitor 2 by a factor of 16
c. Capacitor 1 by a factor of 4
d. Both capacitors store the same energy.
[Ques. 2] Two hoops or rings (I = MR2) are centered, lying on a turntable. The smaller ring has radius = 0.050 m; the larger has radius = 0.10 m. Both have a mass of 6.0 kg. What is the total moment of inertia as the turntable spins? Ignore the mass of the turntable.
a. 0.030 kgm2
c. 0.038 kgm2
b. 0.0075 kgm2
d. 0.075 kgm2
[Ques. 3] A parallel plate capacitor has the voltage applied to it doubled. Is the force between the plates attractive or repulsive, and what happens to the force between the plates when the voltage is doubled?
a. The force is attractive and it quadruples.
b. The force is attractive and it doubles.
c. The force is repulsive and it halves.
d. There is no force between the plates since the net charge is zero on the capacitor.
[Ques. 4] A majorette takes two batons and fastens them together in the middle at right angles to make an x shape. Each baton was 0.90 m long and each ball on the end is 0.20 kg. (Ignore the mass of the rods.) What is the moment of inertia if the arrangement is spun around an axis through the center perpendicular to both rods?
a. 0.064 kgm2
c. 0.075 kgm2
b. 0.096 kgm2
d. 0.16 kgm2
[Ques. 5] A pair of parallel plates, forming a capacitor, are connected to a battery. While the capacitor is still connected to the battery maintaining a constant voltage, the plates are pulled apart to triple their original distance. What is the ratio of the final energy stored to the original energy stored?
a. 1/9
c. 3
b. 1/3
d. 1
[Ques. 6] A majorette takes two batons and fastens them together in the middle at right angles to make an x shape. Each baton was 0.90 m long and each ball on the end is 0.20 kg. (Ignore the mass of the rods.) What is the moment of inertia if the arrangement is spun around an axis formed by one of the batons?
a. 0.081 kgm2
c. 0.19 kgm2
b. 0.064 kgm2
d. 0.32 kgm2
[Ques. 7] A pair of parallel plates, forming a capacitor, are charged. The plates are pulled apart to triple the original separation, the charges on the plates remaining the same. What is the ratio of the final energy stored to the original energy stored?
a. 1/9
c. 1/3
b. 1.5
d. 3
[Ques. 8] A bucket of water with total mass 23 kg is attached to a rope, which in turn is wound around a 0.050-m radius cylinder at the top of a well. The bucket is raised to the top of the well and released. The bucket is moving with a speed of 6.0 m/s upon hitting the water surface in the well. What is the angular speed of the cylinder at this instant?
a. 39 rad/s
c. 120 rad/s
b. 79 rad/s
d. 160 rad/s
[Ques. 9] Two capacitors with capacitances of 1.0 mF and 0.50 mF, respectively, are connected in series. The system is connected to a 50-V battery. What electrical potential energy is stored in the 1.0-mF capacitor?
a. 5.6 10-4 J
c. 0.065 10-3 J
b. 4.3 10-3 J
d. 1.4 10-4 J
[Ques. 10] A baseball pitcher loosens up his pitching arm. He tosses a 0.20-kg ball using only the rotation of his forearm, 0.32 m in length, to accelerate the ball. What is the moment of inertia of the ball alone as it moves in a circular arc with a radius of 0.32 m?
a. 1.5 10-2 kgm2
c. 4.0 10-2 kgm2
b. 2.0 10-2 kgm2
d. 7.6 10-2 kgm2
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