Question 1

A point charge $$q is $$placed at the origin. What is the electric field $$E at a $$distance $$r$$ from the charge in vacuum?

Accepted Answer

$$E = \frac{q}{4\pi\$$epsilon_0$$ r^2$}$$

Question 2

Which of the following correctly describes the potential energy $$U of a $$system of two point charges $$q_1$$ and $$q_2$$ separated by a distance $$r$$?

Accepted Answer

$$U = \frac{q_1$ q_2$}{4\pi\$$epsilon_0$$ r}$$

Question 3

A resistor of resistance $$R is $$connected in series with a capacitor $$C$$ and a battery of emf $$V_0. $$What is the time constant $$	au of $$the circuit?

Accepted Answer

$$	au = RC$$

Question 4

In an RC circuit, what is the voltage across the capacitor $$V_C$$ after a long time when connected to a battery of emf $$V_0$$?

Accepted Answer

$$V_C = V_0$

Question 5

Which of the following best describes the magnetic field $$B$$ produced at the center of a circular loop of radius $$R$$ carrying current $$I$$?

Accepted Answer

$$B = \frac{\mu_0$ I}{2R}$$

Question 6

A charged particle of charge $$q$$ and velocity $$\vec{v}$$ moves in a uniform magnetic field $$\vec{B}. $$What is the magnitude of the force acting on the particle?

Accepted Answer

$$F = qvB \sin	heta$$

Question 7

Which law is used to determine the direction of the induced current in a loop due to a changing magnetic field?

Accepted Answer

Lenz's Law

Question 8

A battery with emf $$\mathcal{E}$$ and internal resistance $$r is $$connected to an external resistor $$R. $$What is the current $$I in $$the circuit?

Accepted Answer

$$I = \frac{\mathcal{E}}{R + r}$$

Question 9

Which of the following is the correct application of Kirchhoff's loop rule in a simple circuit containing a battery, resistor, and capacitor?

Accepted Answer

$$V_{battery} - V_{resistor} - V_{capacitor} = 0$$

Question 10

A capacitor of capacitance $$C is $$charged to a voltage $$V. $$What is the energy stored in the capacitor?

Accepted Answer

$$U = \frac{1}{2}CV^2$

Question 11

Which rule is used to determine the direction of the magnetic field around a current-carrying wire?

Accepted Answer

Right-hand rule

Question 12

A non-uniform charge distribution creates an electric field. Which law can be used to calculate the electric field at a point outside the distribution?

Accepted Answer

Gauss's Law

Question 13

A capacitor is discharging through a resistor. What is the charge $$Q on $$the capacitor at time $$t if $$the initial charge is $$Q_0$$?

Accepted Answer

$$Q = Q_0$ e$$^{-t/RC}$$

Question 14

Which of the following statements about the motion of a charged particle in a uniform magnetic field is correct?

Accepted Answer

The particle moves in a circular path if its velocity is perpendicular to the field.

Question 15

A circuit contains a battery, a resistor, and a capacitor. If the battery is removed after the capacitor is fully charged, what happens?

Accepted Answer

The capacitor discharges through the resistor.

Question 16

Which of the following best describes the effect of increasing the resistance in an RC circuit on the time constant?

Accepted Answer

The time constant increases.

Question 17

A wire carries a current $$I. $$According to the right-hand rule, if your thumb points in the direction of the current, what do your fingers indicate?

Accepted Answer

The direction of the magnetic field lines around the wire.

Question 18

A battery with emf $$\mathcal{E}$$ and internal resistance $$r is $$used to charge a capacitor $$C$$ through a resistor $$R. $$What is the initial current $$I_0$$ just after the circuit is closed?

Accepted Answer

$$I_0$$ = \frac{\mathcal{E}}{R + r}$$

Question 19

Which of the following is true about the potential at a point due to multiple point charges?

Accepted Answer

The potential is the algebraic sum of the potentials due to each charge.

Study Notes: Electricity and Magnetism Fundamentals

Study Guide - Practice Questions

Study Guide - Flashcards