Exams › JEE Main › Physics

An electric field in a region is given by E = 30x²î. What is the potential difference V_A - V_O, if V_O is the potential at the origin and V_A is the potential at the point x = 2 m?

1. 120 J/C
2. -120 J/C
3. -80 J/C
4. 80 J/C

Correct answer: -80 J/C

Solution

The potential difference is calculated by integrating the electric field over the distance from the origin to the point at x = 2 m. Since the electric field is positive in the direction of increasing x, moving against the field results in a decrease in potential, leading to a negative value for the potential difference.

Related JEE Main Physics questions

• If an electric field vector E exists in a material whose dielectric constant is K, and ε0 denotes the permittivity of free space, which expression gives the electric displacement vector?
• If a unit positive charge is taken from point A to point B along the same equipotential surface, then what can be said about the potential difference V_A - V_B?
• Two thin metallic spherical shells are placed concentrically with radii R1 and R2, where R1 > R2. If the shells carry charges Q1 and Q2 respectively, what is the electric potential at a point located at distance r such that R2 < r < R1? (Take k = 1/(4πϵ0))
• An alpha particle is made to move through a potential difference of 10⁶ V. What kinetic energy does it gain?
• A parallel-plate capacitor has its entire gap filled with a dielectric whose dielectric constant changes with position x according to K(x) = K0 + λx, where λ is a constant. How is its capacitance C related to the vacuum capacitance C0?
• Two thin circular rings of radius R each are kept on the same axis with their centres separated by a distance d. One ring carries charge +q and the other carries charge −q. What is the potential difference between the centres of the two rings?

⚔️ Practice JEE Main Physics free + battle 1v1 →