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Moving Charges and Magnetism — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsMoving Charges and Magnetism1 Mark
MCQ
Let $\overrightarrow{\text{E}}$ and $\overrightarrow{\text{B}}$ denote electric and magnetic fields in a frame S and $\overrightarrow{\text{E}}$ and $\overrightarrow{\text{B}}$ in another frame S moving with respect to S at a velocity $\overrightarrow{\text{v}}.$ Two of the following equations are wrong. Identify them.
  • A
    $\text{B}_\text{y},=\text{B}_\text{y}+\frac{\text{vE}_\text{z}}{\text{c}^2}$
  • B
    $\text{E}_\text{y},=\text{E}_\text{y}+\frac{\text{vB}_\text{z}}{\text{c}^2}$
  • C
    $\text{B}'_\text{y}=\text{B}_\text{y}+\text{v}\text{E}_\text{z}$
  • ✓
    B and C both
✓

Answer

Correct option: D.
B and C both
Explanation:
$\text{qE}=\text{qvB}$
$\Rightarrow\text{e}=\text{vB}$ By dimensionally b & care wrong
$\Rightarrow\text{v}\text{E}=\text{v}^2\text{B}$
$\Rightarrow\text{B}=\frac{\text{vE}}{\text{v} ^2}$

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