Question 1

Which of the following statements about electric charge is correct?

Accepted Answer

None of the statements are true.

Question 2

A single charge $$q = +1\ \mu	ext{C} is $$located at the origin and surrounded by four different objects: A and B are point charges 50 cm away, C is a spherical metal shell (radius 15 cm, center 50 cm away on the y-axis), and D is a solid metal sphere (radius 15 cm, center 50 cm away on the z-axis). If charge $$q is $$allowed to freely move, in which direction would it start moving?

Accepted Answer

It doesn’t move.

Question 3

An electron is initially moving to the right with speed $$v$$ when it enters a uniform electric field directed upwards. Which trajectory will the electron follow?

Accepted Answer

Trajectory C (curves downward)

Question 4

Refer to the electric field diagram with charges P and Q. Consider the statements: (i) The charge on P is smaller than the charge on Q. (ii) The electrostatic force on P is smaller than the force on Q. Which is correct?

Accepted Answer

Only (i) is true.

Question 5

When an electron enters an electric field region and follows a curved trajectory, which statement correctly describes its electric potential energy?

Accepted Answer

It is moving from high potential to low potential and losing electric potential energy.

Question 6

A battery charges a parallel-plate capacitor fully and is then removed. The plates are slowly pulled apart. Which phenomena will happen?

Accepted Answer

(i) and (iii): The potential difference increases and the capacitance decreases.

Question 7

Which statement is NOT true about a perfect conductor placed in a steady external electric field?

Accepted Answer

The surface of the conductor is electrically neutral.

Question 8

Two parallel-plate capacitors store the same charge $$Q. $$Capacitor 2 is filled with a dielectric of constant $$\kappa \u003e 1. $$Which statements are correct?

Accepted Answer

Only (ii): The potential energy stored in Capacitor 1 is larger than that in Capacitor 2.

Question 9

A parallel-plate capacitor with plates spaced $$1\ 	ext{mm}$$ apart is charged to $$500\ 	ext{V}. A $$proton is fired through a hole in the negative plate with speed $$4.0 	imes 10^5$\ 	ext{m/s}. $$Which statement about the calculation of how far the proton travels before stopping is NOT true?

Accepted Answer

The final answer in (3) suggests the proton will stop before it strikes the positive plate.

Question 10

The conditions for dark fringes in single-slit interference are given by $$W \sin 	heta = m\lambda$$, $$m = \pm 1, \pm 2, \pm 3, .... $$Which change increases the separation between bright fringes in a diffraction pattern?

Accepted Answer

Increase the wavelength of the light used.

Question 11

For a successful Young’s double-slit experiment, the light source must be not only monochromatic but also coherent.

Accepted Answer

True

Question 12

Electrically neutral objects cannot exert an electrical force on each other, but they can exert a gravitational force on each other.

Accepted Answer

True

Question 13

As a proton moves perpendicular to electric field lines, what happens to its electric potential and electric potential energy?

Accepted Answer

Both remain constant.

Question 14

A hydrogen nucleus ($$+e) is to $$the left of a carbon nucleus ($$+6e). $$The electrical force experienced by the hydrogen nucleus is to the left, and its magnitude is greater than the force exerted on the carbon nucleus.

Accepted Answer

False

Question 15

If the electric potential at a point in space is zero, then the electric field at that point must be zero.

Accepted Answer

False

Question 16

A parallel-plate capacitor is filled with a dielectric material of constant $$\kappa. If $$the plates are separated by distance $$d$$ and area $$A$$, what is the new capacitance?

Accepted Answer

$$C = \frac{\kappa \$$varepsilon_0$$ A}{d}$$

Question 17

A proton moves from a region of higher electric potential to lower electric potential. What happens to its kinetic energy?

Accepted Answer

It increases.

Question 18

Which of the following best describes the relationship between electric field lines and electric potential?

Accepted Answer

Electric field lines point from regions of high potential to low potential.

Question 19

A charged particle is placed in a region with a uniform electric field. If the particle is released from rest, what will its motion be?

Accepted Answer

It will accelerate in the direction opposite to the electric field.

Question 20

Which of the following is a correct expression for the electric potential energy $$U of a $$system of two point charges $$q_1$$ and $$q_2$$ separated by distance $$r$$?

Accepted Answer

$$U = \frac{q_1$ q_2$}{4\pi \$$varepsilon_0$$ r}$$

Electric Fields, Conductors, Capacitors, and Interference: Step-by-Step Physics Review

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