EZ Electrostatics Quiz

A capacitor is constructed of two identical conducting plates parallel to each other and separated by a distance d. The capacitor is charged to a potential difference of V0 by a battery, which is then disconnected.

A sheet of insulating plastic material is inserted between the plates without otherwise disturbing the system. What effect does this have on the capacitance?

• It causes the capacitance to increase

• It causes the capacitance to decrease

• None; the capacitance does not change

• Nothing can be said about the effect without knowing the dielectric constant of the plastic

• Nothing can be said about the effect without knowing the thickness of the sheet.

Two small spheres are arranged along a line and carry charges of +4Q and –3Q, as shown in the figure above. The vertical lines are equally spaced.

At which of the labeled points does the electric field point toward the right with the smallest magnitude?

• A

• B

• C

• D

• E

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-5

A charge +𝑄 is inside a hollow region in an electrically neutral piece of solid metal, as shown above. The dashed line represents a Gaussian surface within the metal that completely encloses the hollow region.

At which of the three labeled points is the electric field equal to zero?

• X only

• Y only

• X and Z only

• Y and Z only

• X, Y, and Z

Tags

NGSS.HS-PS2-4

A battery or batteries connected to two parallel plates produce the equipotential lines between the plates shown above.

The force on an electron located on the 0-volt potential line is

• 0 N

• 1 N, directed to the right

• 1 N, directed to the left

• directed to the right, but its magnitude cannot be determined without knowing the the distance between the lines

• directed to the left, but its magnitude cannot be determined without knowing the distance between the lines

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-5

A battery or batteries connected to two parallel plates produce the equipotential lines between the plates shown above.

The force on an electron located on the 0-volt potential line is

• Q₂ = 16Q₁

• Q₂ = 4Q₁

• Q₂ = Q₁

• Q₂ = 0.25Q₁

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-5

The above circuit is designed with an ideal battery and a capacitor. When the capacitor is fully charged, the charge on the capacitor plates has a magnitude Q. Which of the following is a correct hypothesis for what will happen to the capacitor when a material of dielectric constant κ is inserted between the capacitor plates?

• The charge stored on the capacitor will increase

• The charge stored on the capacitor will decrease

• The potential difference across the plates of the capacitor will increase

• The potential difference across the plate of the capacitor will decrease

• The energy stored on the capacitor will remain the same

If a dielectric is inserted between the plates of a capacitor while the capacitor maintains its connection to a constant voltage source, which of the following is true?

• The capacitance of the capacitor is unchanged

• The charge on the capacitor plates increases

• The potential difference across the capacitor increases

• The electric field between the capacitor plates increases

• The electric field between the capacitor plates decreases

In the given figure, determine the point (other than

infinity) at which the electric field is zero.

• 1.82 m to the left of the -2.50 μC charge

• 1.82 m to the right of the -2.50 μC charge

• 0.392 m to the left of the -2.50 μC charge

• 0.392 m to the right of the -2.50 μC charge

Tags

NGSS.HS-PS2-4

A proton is projected in the +x direction into a region of a uniform electric field E = (-6.00 x 105) N/C, also in the +x direction at t = 0. The proton travels 7.00 cm as it comes to rest. Determine the initial speed of the proton.

• $2.84\times10^6\ \frac{m}{s}$

• $8.06\times10^{14}\ \frac{m}{s}$

• $2.84\times10^7\ \frac{m}{s}$

• $8.06\times10^{12}\ \frac{m}{s}$

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4

When uncharged bits of paper are brought near a charged comb:

• There is no interaction because the paper is not charged.

• There is no interaction because the paper is too heavy to move.

• There is attraction because the paper is a dielectric.

• There is repulsion because the paper is a dielectric.

Tags

NGSS.HS-PS2-4