QCEVault

Electromagnetic induction — Question 26

Original QCE Vault practice · 1 mark

Q26 · Practice questionSimple familiar1 mark

QUESTION 26

An antenna is driven by an alternating current so that electrons oscillate back and forth. Which explanation best accounts for the radio wave emitted by the antenna?
(A)
The electrons create only a static electric field.
(B)
The accelerating charges produce changing electric and magnetic fields that propagate outward.
(C)
The antenna emits gravitational waves because the electrons have mass.
(D)
A constant magnetic field carries energy away from the antenna.
Question linkSyllabus coverage

Related questions

  1. Q21 · Original practice · 1 mark
    A uniform magnetic field of 0.50 T0.50\,\text{T} passes through a loop of area 0.030 m20.030\,\text{m}^2. The field is at 60∘60^\circ to the loop normal. What is the magnetic flux?
    Electromagnetic induction
  2. Q22 · Original practice · 1 mark
    The magnetic flux through each turn of a 120120-turn coil changes by 4.0×10−3 Wb4.0\times10^{-3}\,\text{Wb} in 0.080 s0.080\,\text{s}. What is the magnitude of the average induced EMF?
    Electromagnetic induction
  3. Q23 · Original practice · 1 mark
    The south pole of a bar magnet approaches the left face of a conducting coil, as shown. According to Lenz’s law, the left face of the coil initially behaves as
    Electromagnetic induction
  4. Q24 · Original practice · 1 mark
    An ideal transformer has 600600 primary turns and 150150 secondary turns. If the primary voltage is 240 V240\,\text{V}, the secondary voltage is
    Electromagnetic induction