[amp_mcq option1=”Magnetic field” option2=”Sound waves” option3=”Light rays” option4=”Heat waves” correct=”option1″]
The correct answer is A. Moving electric charge produces a magnetic field.
A magnetic field is a region of space where a magnetic force is exerted on moving electric charges. The magnetic field is produced by the motion of electric charges, and it can also exert a force on moving charges.
The magnetic field is a vector field, which means that it has both magnitude and direction. The direction of the magnetic field is perpendicular to the plane of the electric current and the direction of the magnetic field lines.
The magnitude of the magnetic field is proportional to the strength of the electric current and the distance from the current.
The magnetic field is used in many different applications, including electric motors, generators, and loudspeakers.
Option B is incorrect because sound waves are produced by the vibration of matter. Option C is incorrect because light rays are produced by the vibration of electric and magnetic fields. Option D is incorrect because heat waves are produced by the vibration of atoms and molecules.