A) 2400 V/cm
B) 600 V/cm
C) 1200 V/cm
D) 12000 V/cm
Correct Answer: C
Solution :
Cathode ray are composed of electrons, \[F=eE\] \[\Rightarrow \] \[F=\frac{m{{v}^{2}}}{r}\] \[\Rightarrow \] \[eE=\frac{m{{v}^{2}}}{r}\] \[\Rightarrow \] \[r=\frac{m{{v}^{2}}}{eE}=\frac{m{{({{10}^{6}})}^{2}}}{e(300)}\] When velocity is doubled same circular path is followed hence radius is same \[r=\frac{m{{(2\times {{10}^{6}})}^{2}}}{eE}\] \[\frac{m\times {{({{10}^{6}})}^{2}}}{300}=\frac{m\times {{(2\times {{10}^{6}})}^{2}}}{eE}\] \[E=300\times 4=1200\,V/cm\]You need to login to perform this action.
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