Question 1

Which law states that the induced emf in a circuit is directly proportional to the rate of change of magnetic flux linkage?

Accepted Answer

Faraday's Law of Electromagnetic Induction

Question 2

A wire carries a current upward. Using the Right-Hand Rule, what is the direction of the magnetic field around the wire?

Accepted Answer

Counterclockwise when viewed from above

Question 3

What is the formula for magnetic flux through a surface?

Accepted Answer

$$\Phi = B A \cos 	heta$$

Question 4

A coil with 200 windings and area $$2.8 	imes 10$$^{-3}$$ 	ext{ m}^2 is $$rotated in a $$2.5 	ext{ T}$$ field. If the angle changes from $$0^\circ to$$ $$90^\circ$$, what is the change in magnetic flux?

Accepted Answer

$$-0.007 	ext{ Wb}$$

Question 5

Which of the following is true for Ohmic conductors?

Accepted Answer

Current is directly proportional to voltage

Question 6

What is the correct formula for Ohm’s Law?

Accepted Answer

$$I = \frac{V}{R}$$

Question 7

Which of the following is a non-ohmic conductor?

Accepted Answer

Lightbulb

Question 8

For three resistors $$R_1$$, $$R_2$$, and $$R_3 in $$series, what is the total resistance?

Accepted Answer

$$R_s = R_1$ + R_2$ + R_3$

Question 9

For three resistors $$R_1$$, $$R_2$$, and $$R_3 in $$parallel, what is the total resistance?

Accepted Answer

$$\frac{1}{R_p} = \frac{1}{R_1$} + \frac{1}{R_2$} + \frac{1}{R_3$}$$

Question 10

A lightbulb rated at 60 W is used for 2.5 hours. If the tariff is 164.29 c/kWh, what is the cost to operate the bulb?

Accepted Answer

R0.25

Question 11

What is the unit of magnetic flux?

Accepted Answer

Weber (Wb)

Question 12

Which statement best describes the environmental impact of overhead power lines?

Accepted Answer

They can harm birds through electrocution and collisions.

Question 13

If a magnet is moved toward a coil, what is the direction of the induced current according to Lenz’s Law?

Accepted Answer

It opposes the approaching magnetic field.

Question 14

A solenoid is exposed to a moving north pole. What is the direction of the induced current?

Accepted Answer

Counterclockwise to generate a north pole

Question 15

What is the formula for electrical power in terms of current and voltage?

Accepted Answer

$$P = IV$$

Question 16

A resistor has a voltage of 10 V and a current of 2 A. What is the power dissipated?

Accepted Answer

20 W

Question 17

Which formula can be used to calculate the energy transferred in a resistor over time?

Accepted Answer

$$W = IV \Delta t$$

Question 18

If the resistance of a bulb is 2 Ω and the current is 2.4 A, what is the voltage across the bulb?

Accepted Answer

4.8 V

Question 19

What happens to the brightness of a bulb as more resistors are connected in parallel in the circuit?

Accepted Answer

It increases

Question 20

A geyser rated at 2000 W is used for 5 hours per day. What is the energy used per day in kWh?

Accepted Answer

2 kWh

Electromagnetism and Electric Circuits: Study Notes for College Physics

Guida di studio - Domande di pratica

Study guide - Flashcard