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A charge particle is moving in a uniform magnetic field \mathrm{(2 \hat{i}+3 \hat{j})\; \mathrm{T}.} If it has an acceleration of \mathrm{(\alpha \hat{i}-4 \hat{j}) \; ^\mathrm{m} / \mathrm{s}^{2}}, then the value of \mathrm{\alpha} will be :

Option: 1

3


Option: 2

6


Option: 3

12


Option: 4

2


Answers (1)

best_answer

\mathrm{\bar{B}=2 \hat{i}+3 \hat{\jmath} }

\mathrm{\bar{a}=\alpha \hat{i}-4 \hat{\jmath} }

In magnetic field, the force vector and magnetic field vector are perpendicular to each other
i.e.   \mathrm{ \bar{F} \perp \bar{B}}

\mathrm{\therefore \quad \bar{a} \perp \bar{B}}

\mathrm{\bar{a}\rightarrow acceleration\: vector}

\mathrm{ \bar{a} \cdot \bar{B}= a\: B cos\: 90^{\circ}=0}

\mathrm{2 \alpha-12=0}

\mathrm{\alpha =6}

Hence (2) is correct option.
 

Posted by

Pankaj Sanodiya

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