Question 1

A sound wave travels through air with a frequency of $$440\ \mathrm{Hz}$$ and a wavelength of $$0.78\ \mathrm{m}. $$What is the speed of sound in air based on these values?

Accepted Answer

$$343\ \mathrm{m/s}$$

Question 2

Which of the following best describes the difference between a transverse wave and a longitudinal wave?

Accepted Answer

In a transverse wave, particle displacement is perpendicular to wave direction; in a longitudinal wave, displacement is parallel to wave direction.

Question 3

Two waves of equal amplitude and frequency travel in opposite directions and overlap. What phenomenon results, and what is a key feature of this phenomenon?

Accepted Answer

Standing wave; nodes and antinodes are formed at fixed positions.

Question 4

A neutral metal sphere is brought near a negatively charged rod but does not touch it. The sphere becomes polarized. What happens to the charges in the sphere?

Accepted Answer

Electrons in the sphere are repelled, causing one side to become more positive and the other more negative.

Question 5

Which of the following statements about electric field and electric force is correct?

Accepted Answer

Electric field is a property of space around a charge, while electric force is the interaction experienced by another charge in that field.

Question 6

A plastic rod is rubbed with wool and becomes negatively charged. Which charging method is this, and what happens at the atomic level?

Accepted Answer

Friction; electrons are transferred from the wool to the rod.

Question 7

A $$12\ \mathrm{V}$$ battery is connected to a resistor, and a current of $$2\ \mathrm{A}$$ flows. What is the resistance of the resistor?

Accepted Answer

$$6\ \Omega$$

Question 8

Why are household electrical circuits wired in parallel rather than in series?

Accepted Answer

So that each device receives the full voltage and can operate independently.

Question 9

Which of the following best describes the difference between AC and DC circuits?

Accepted Answer

AC current reverses direction periodically, while DC current flows in one direction only.

Question 10

A device operates at $$120\ \mathrm{V}$$ and draws $$5\ \mathrm{A} of $$current. What is the power consumed by the device?

Accepted Answer

$$600\ \mathrm{W}$$

Question 11

Which of the following statements about magnetic fields is correct?

Accepted Answer

A moving electric charge produces a magnetic field.

Question 12

What is the main difference between a standard (permanent) magnet and an electromagnet?

Accepted Answer

An electromagnet requires electric current to produce a magnetic field, while a permanent magnet does not.

Question 13

A wire carrying current is placed in a magnetic field. What happens to the wire?

Accepted Answer

It experiences a force perpendicular to both the current and the magnetic field.

Question 14

Which of the following best describes electromagnetic induction?

Accepted Answer

The process of generating an electric current by changing the magnetic field through a conductor.

Question 15

According to Faraday’s Law, what determines the magnitude of the induced voltage in a coil?

Accepted Answer

The rate of change of magnetic flux through the coil.

Question 16

A transformer has $$100$$ turns on its primary coil and $$400$$ turns on its secondary coil. If the input voltage is $$120\ \mathrm{V}$$, what is the output voltage?

Accepted Answer

$$480\ \mathrm{V}$$

Question 17

Why is electric power transmitted over long distances at high voltage and low current?

Accepted Answer

To minimize energy loss due to resistance in the transmission lines.

Question 18

A generator converts mechanical energy into electrical energy. Which principle explains this process?

Accepted Answer

Electromagnetic induction, as described by Faraday’s Law.

Question 19

Which of the following is true about electric potential and electric potential energy?

Accepted Answer

Electric potential is the potential energy per unit charge.

Question 20

A $$60\ \mathrm{W}$$ light bulb is connected to a $$120\ \mathrm{V}$$ outlet. What is the current through the bulb?

Accepted Answer

$$0.5\ \mathrm{A}$$

Physics Study Guide: Waves, Electricity, Magnetism, and Electromagnetic Induction

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