An electric field is expressed as \(\vec{E}=2 \hat{i}+3 \hat{j}\). Find the potential difference…
An electric field is expressed as \(\vec{E}=2 \hat{i}+3 \hat{j}\). Find the potential difference \(\left(V_{A}-V_{B}\right)\) between two points \(A\) and \(B\) whose position vectors are given by \(r_{A}=\hat{i}+2 \hat{j}\) and \(r_{B}=2 \hat{i}+\hat{j}+3 \hat{k}\). Mark modulus of potential difference.
Solution
$\begin{aligned}
v_{f}-v_{i} &= -\int_{i}^{f}\left(E_{x} \hat{i}+E_{y} \hat{j}+E_{z} \hat{k}\right) \cdot(d x \hat{i}+d y \hat{j}+d z \hat{k})\\
V_{B}-V_{A} &=-\left[\int_{i}^{f} E_{x} d x+\int_{i}^{f} E_{y} d y+\int_{i}^{f} E_{z} d z\right] \\
V_{B}-V_{A} &=-\left[\int_{1}^{2} 2 d x+\int_{2}^{1} 3 d y\right] \\
V_{B}-V_{A} &=-[2(2-1)+3(1-2)] \\
V_{B}-V_{A} &=-[2-3]=1 V
\end{aligned}$
Hence, \(V_{A}-V_{B}=-1 V .\) Hence, ans is 1
Asked in: JEE Mains - Electrostatics - Chapter Test