A) 11 cm
B) 1.1 cm
C) 1.1 mm
D) 1.1 m
Correct Answer: B
Solution :
The force exerted on electron moving with velocity\[v\]is \[F=evB\sin \theta \] where\[\theta ={{90}^{o}}\] \[\therefore \] \[{{F}_{B}}=evB\] ... (i) Centripetal force is given by \[{{F}_{C}}=\frac{m{{v}^{2}}}{r}\] ? (ii) Equating Eqs. (i) and (ii), we get \[r=\frac{m{{v}^{2}}}{eB}\] Diameter\[d=2r=\frac{2v}{(e/m)B}\] \[\Rightarrow \] \[d=\frac{2v}{1.76\times {{10}^{11}}\times 2\times {{10}^{-2}}}\] \[=1.1\,\,cm\]You need to login to perform this action.
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