Electrostatics

A hydrogen atom consists of a proton and an electron. If the orbital radius of the electron increases, the electric potential energy of the electron due to the proton a. increases. b. decreases. c. depends on the zero point of the potential. d. remains the same.

A

A proton is accelerated from rest through a potential difference V0 and gains a speed v0. If it were accelerated instead through a potential difference of 2V0, what speed would it gain? a. v0(sqrt2) b. 4v0 c. 2v0 d. 8v0

A

As an electron moves in the direction the electric field lines a. it is moving from high potential to low potential and gaining electric potential energy. b. it is moving from high potential to low potential and losing electric potential energy. c. both its electric potential and electric potential energy remain constant. d. it is moving from low potential to high potential and losing electric potential energy. e. it is moving from low potential to high potential and gaining electric potential energy.

A

If the electric potential at a point in space is zero, then the electric field at that point must be a. impossible to determine based on the information given. b. zero. c. uniform. d. positive. e. negative.

A

If the result of your calculation of a quantity has SI units kg ∙ m2/(s2 ∙ C), that quantity could be a. an electric potential difference. b. a capacitance c. an electric field strength. d. an electric potential energy. e. a dielectric constant.

A

What is the charge on 1.0 kg of protons?(e = 1.60 × 10-19 C, mproton = 1.67 × 10-27 kg) a. 9.6 × 107 C b. 1000 C c. 6.0 × 1026 C d. 1.0 C e. 6.0 × 1023 C

A

At a distance d from a point charge Q, the energy density in its electric field is u. If we double the charge, what is the energy density at the same point? a. 8u b. 4u c. 2u d. u e. 16u

B

If the result of your calculations for a quantity has SI units of C2 ∙ s2/(kg ∙ m2), that quantity could be a. an electric potential energy. b. a capacitance. c. a dielectric constant. d. an electric field strength. e. an electric potential difference.

B

A proton and an electron are released from rest, with only the electrostatic force acting. Which of the following statements must be true about them as they move toward each other? (There could be more than one correct choice.) a. Their electric potential energy keeps increasing. b. Their kinetic energy keeps increasing. c. Their acceleration keeps decreasing. d. Their kinetic energy keeps decreasing. e. Their electric potential energy keeps decreasing.

B E

As a project we will be build a device called an Electrostatic precipitator, which is used to remove smoke from chimneys such as in coal factories. How does this thing work? a. well it's a square faraday cage so that any smoke that goes inside is trapped b. I think it's like a fur/stick thing to charge up the smoke, and then a neutral plate to polarize and attract the smoke c. It's basically a tesla coil inside a capacitor so that smoke gets charged and then attracted to an oppositely charged wall. d. ok it's a whimhurst like machine that uses static electricity to charge up the smoke so they repel another stronger than gravity

C

If the electric potential at a point in space is zero, then the electric field at that point must be a. uniform. b. positive. c. impossible to determine based on the information given. d. negative. e. zero.

C

The potential (relative to infinity) at the midpoint of a square is 3.0 V when a point charge of +Q is located at one of the corners of the square. What is the potential (relative to infinity) at the center when each of the other corners is also contains a point charge of +Q? a. 3.0 V b. 0 V c. 12 V d. 9.0 V

C

Which of these must not be zero inside a Faraday cage? Select one: a. electric field b. change (gradient) in voltage c. voltage d. force on any test charge inside the charge

C

Two protons are fired toward each other in a particle accelerator, with only the electrostatic force acting. Which of the following statements must be true about them as they move closer together? (There could be more than one correct choice.) a. Their kinetic energy keeps increasing. b. Their acceleration keeps decreasing. c. Their kinetic energy keeps decreasing. d. Their electric potential energy keeps decreasing. e. Their electric potential energy keeps increasing.

C E

As a proton moves in the direction the electric field lines a. it is moving from high potential to low potential and gaining electric potential energy. b. it is moving from low potential to high potential and losing electric potential energy. c. it is moving from low potential to high potential and gaining electric potential energy. d. it is moving from high potential to low potential and losing electric potential energy. e. both its electric potential and electric potential energy remain constant.

D

The electric field inside a metallic conductor is a. negative b. positive c. unifrom d. 0

D

The electron-volt is a unit of a. charge. b. electric field. c. electric force. d. energy. e. electric potential.

D

Two electrons are 20mm apart at closest approach. What is the magnitude of the maximum electric force that they exert on each other? (e = 1.60 × 10-19 C, k = 1/4πε0 = 9.0 109 N ∙ m2/C2) a. 5.8 × 10-27 N b. -2.3 N c. -2.3 × 1010 N d. 5.8 × 10-25 N

D

As a proton moves in a direction perpendicular to the electric field lines a. it is moving from low potential to high potential and losing electric potential energy. b. it is moving from high potential to low potential and losing electric potential energy. c. it is moving from low potential to high potential and gaining electric potential energy. d. it is moving from high potential to low potential and gaining electric potential energy. e. both its electric potential and electric potential energy remain constant.

E

At a distance d from a point charge Q, the energy density in its electric field is u. If we now go to a distance d/2 from the charge, what is the energy density at the new location? a) 2u b) 8u c) 4u d) u√2 e) 16u

E

If the result of your calculation of a quantity has SI units of kg ∙ m/(s2 ∙ C), that quantity could be a. an electric potential difference. b. an electric potential energy. c. a capacitance d. a dielectric constant. e. an electric field strength.

E

If the result of your calculation of a quantity has SI units of kg ∙ m/(s^2 ∙ C), that quantity could be a. a dielectric constant. b. a capacitance c. an electric potential energy. d. an electric potential difference. e. an electric field strength.

E

The electric potential at a distance of 4 m from a certain point charge is 200 V relative to infinity. What is the potential (relative to infinity) at a distance of 2 m from the same charge? a. 100 V b. 50 V c. 600 V d. 200 V e. 400 V

E

What is the electric field of a typical AA battery if it measures about 0.02m long and has a voltage reading of 1.6V? a. 1.6*1.6e-19 b. 1.6/1.6e-19 c. 1.6 d. 1.6*.02 e. 1.6/.02

E