The electric potential \(\mathrm{V}\) at any point $\mathrm{x}, \mathrm{y}, \mathrm{z}\( (all in meter) in space is given by \)\mathrm{V}=4 \mathrm{x}^{2}$ volt. The electric field at the point \((1 \mathrm{~m}, 0,2 \mathrm{~m})\) in \(\mathrm{Vm}^{-1}\) is \((\mathrm{A})+8 \mathrm{i} \wedge\) (B) \(-8 \mathrm{i} \wedge\) (C) \(-16 \mathrm{i}\) (D) \(+16 \mathrm{i}\)

Short Answer

Expert verified
The electric field at point \((1\ \mathrm{m}, 0, 2\ \mathrm{m})\) is \((B)\ -8\vec{i}\ \mathrm{Vm}^{-1}\).

Step by step solution

01

Find the derivative of the potential function with respect to x

Given \(V = 4x^2\) (y and z do not affect V). We will differentiate V with respect to x: \[ \frac{\partial V}{\partial x} = \frac{d(4x^2)}{dx} = 8x \]
02

Calculate the x-component of the electric field Ex using the formula E = -∇V

The x-component of the electric field Ex is given by: \[ Ex = -\frac{\partial V}{\partial x} = -8x \]
03

Evaluate Ex at the given point (1m, 0, 2m)

To find the electric field at the point (1m, 0, 2m), we plug in x=1 into Ex: \[ Ex = -8(1) = -8\ \mathrm{Vm}^{-1} \] So, the electric field at the given point is -8 Vm^{-1} in the x-direction. Checking the given options, we can conclude that the correct answer is: (B) \(-8\vec{i}\ \mathrm{Vm}^{-1}\)

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Most popular questions from this chapter

A parallel plate air capacitor has a capacitance \(18 \mu \mathrm{F}\). If the distance between the plates is tripled and a dielectric medium is introduced, the capacitance becomes \(72 \mu \mathrm{F}\). The dielectric constant of the medium is (A) 4 (B) 12 (C) 9 (D) 2

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