Question

Determine which one of the following statement(s) IS NOT TRUE.

a.A constant electric current creates a magnetic field.
b.The magnetic field B created by an changing electric field E is perpendicular to E.
c.A changing electric current creates a magnetic field.
d.A changing electric field cannot create a magnetic field without a conductive wire.
e.A changing amount of charges in a capacitor creates a magnetic field.

Answer 1

Option (d) is not true; a changing electric field can produce a magnetic field without the presence of a conductive wire, according to Maxwell's equations.

Step-by-step explanation:

We need to determine which statement about electric and magnetic fields is not true. Option (a) states that a constant electric current creates a magnetic field, which is true as confirmed by Oersted's experiments and Ampere's law. Possibility (b) suggests that the magnetic field B created by an changing electric field E is perpendicular to E, which is in accordance with Faraday's law of induction. For option (c), it's accurate that a changing electric current also creates a magnetic field, which is a foundational principle in electromagnetism and the basis for electromagnetic waves. However, option (d) states that a changing electric field cannot create a magnetic field without a conductive wire. This is not true; according to Maxwell's equations, a changing electric field can produce a magnetic field regardless of a conductive wire presence, which is the principle behind the displacement current. Lastly, option (e) indicates that a changing amount of charges in a capacitor creates a magnetic field, which is how the concept of displacement current was originally described by Maxwell. Hence, the statement in option (d) is not true.