Download App

Electromagnetic Waves — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsElectromagnetic Waves1 Mark
MCQ
A free electron is placed in the path of a plane electromagnetic wave. The electron will start moving:
  • ✓
    Along the electric field.
  • B
    Along the magnetic field.
  • C
    Along the direction of propagation of the wave.
  • D
    In a plane containing the magnetic field and the direction of propagation.
✓

Answer

Correct option: A.
Along the electric field.

As the electron is at rest initially, only the electric field will exert force on it. There will be no magnetic force on the electron in the stating. Hence, the electron will start moving along the electric field.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from Electromagnetic Waves→Electromagnetic Waves — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

A charge of total amount $Q$ is distributed over two concentric hollow spheres of radii $r$ and $R ( R > r)$ such that the surface charge densities on the two spheres are equal. The electric potential at the common centre is
→
A transformer is employed to reduce 220 V to 11 V. The primary draws a current of 5 A and the secondary 90 A. The efficiency of the transformer is
→
A point object $O$ is placed in front of a glass rod having spherical end of radius of curvature $30 cm.$ The image would be formed at
→
Assertion : Cobalt $-60$ is useful in cancer therapy.

Reason : Cobalt $-60$ is a source of $\gamma  - $ radiations capable of killing cancerous cells

→
If a source of power $4\ kW$ produces $10^{20}$ photons/second , the radiation belongs to a part of the spectrum called
→
An element $\Delta l=\Delta \mathrm{xi}$ is placed at the origin and carries a large current $\mathrm{I}=10 \mathrm{~A}$. The magnetic field on the $y$-axis at a distance of $0.5 \mathrm{~m}$ from the elements $\Delta \mathrm{x}$ of $1 \mathrm{~cm}$ length is:
→
Two long current carrying thin wires, both with current $I$, are held by insulating threads oflength $L$ and are in equilibrium as shown in the figure, with threads making an angle '$\theta$' with the vertical. If wires have mass $\lambda$ per unit length then the value of $l$ is 
($g =$ gravitational acceleration)
→
What is the current in the circuit shown below
→
Figure shows a conducting loop $A D C A$ carrying current $i$ and placed in a region of uniform magnetic field $B_0$. The part $A D C$ forms a semicircle of radius $R$. The magnitude of force on the semicircle part of the loop is equal to
→
In a radio tuning $RLC$ circuit, the half power frequencies are $100\,MHz$ and $120\,MHz$. Find the quality factor
→