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A particle mass m and charge q is in an electric and magnetic field is given by \overrightarrow{E} = 2\widehat{i}+3\widehat{j}; \overrightarrow{B} = 4\widehat{j}+6\widehat{k}. The charged particle is shifted from the origin to the point P(x = 1, y = 1)along a straight path. The magnitude of the total work done is:

 

  • Option 1)

    (0.15)q

  • Option 2)

    (0.35)q

     

  • Option 3)

    5q

  • Option 4)

    (2.5)q

Answers (1)

best_answer

 

Force on a charged particle in magnetic field -

\underset{F}{\rightarrow}=q (\underset{V}{\rightarrow}\times \underset{B}{\rightarrow})

F=qVB\sin \theta

- wherein

\underset{V}{\rightarrow} - velocity of the particle 

\underset{B}{\rightarrow}  magnetic field 

E=2\hat{i}+3\hat{j}

\vec{B}=4\hat{j}++6\hat{k}

0(0,0)\; \; \; \; \; \; \; \; \; ,\; \; \; \; \; \; \; \; \; \; \; P(1,1)

OP=S=1\hat{i}+1\hat{j}

W=F_{net}\cdot S

\vec{F_{net}}=9\vec{E}+9\left (\vec{V}\times \vec{B} \right )

\vec{V}\times \vec{ B} is perpendicular to \vec{V}

So \vec{V}\times \vec{ B} is perpendicular to \vec{S}

So W_{B}=9\left ( \vec{V}\times \vec{B} \right )\cdot \vec{S}=0

W_{E}=\left ( 9\vec{E} \right )\cdot \vec{S}

         =\left ( 29\hat{i}+39\hat{j} \right )\left ( 1\hat{i} +1\hat{j}\right )

         =29+39

W_{net}=W_{E}+W_{B}=59

 

 

 


Option 1)

(0.15)q

Option 2)

(0.35)q

 

Option 3)

5q

Option 4)

(2.5)q

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