A) \[\left( 10/9 \right)\text{ }volt/\mu m\]and in the +ve x direction
B) \[\left( 5/3 \right)\text{ }volt/\mu m\]and in the -ve x direction
C) \[\left( 5/3 \right)\text{ }volt/\mu m\] and in the +ve x direction
D) \[\left( 10/9 \right)\text{ }volt/\mu m\]and in the -ve x direction
Correct Answer: A
Solution :
[a] Here, \[V\left( x \right)=\frac{20}{{{x}^{2}}-4}volt\] We know that \[E=-\frac{dV}{dx}=-\frac{d}{dx}\left( \frac{20}{{{x}^{2}}-4} \right)\] \[\text{or, }E=+\frac{40x}{{{\left( {{x}^{2}}-4 \right)}^{2}}}\] At\[x=4\mu m\], \[E=+\frac{40\times 4}{{{({{4}^{2}}-4)}^{2}}}=+\frac{160}{144}=+\frac{10}{9}volt/\mu m\]. Positive sign indicates that \[\vec{E}\] is in +ve x-direction.You need to login to perform this action.
You will be redirected in
3 sec