Exams › JEE Main › Physics

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Two metallic spheres are charged to the same potential. One of them is hollow and another is solid, and both have the same radii. Solid sphere will have lower charge than the hollow one. Reason R : Capacitance of metallic spheres depend on the radii of spheres. In the light of the above statements, choose the correct answer from the options given below: (1) Both A and R are true but R is not the correct explanation of A (2) A is false but R is true (3) Both A and R are true but R is the correct explanation of A (4) A is true but R is false

1. (1) Both A and R are true but R is not the correct explanation of A
2. (2) A is false but R is true
3. (3) Both A and R are true but R is the correct explanation of A
4. (4) A is true but R is false

Correct answer: (2) A is false but R is true

Solution

The assertion is incorrect because the charge on a metallic sphere does not depend on whether it is hollow or solid, as both will have the same charge when at the same potential. However, the reason is accurate since the capacitance of metallic spheres does indeed depend on their radii.

Related JEE Main Physics questions

• If an electric field vector $\mathbf{E}$ exists in a material whose dielectric constant is $K$, and $\varepsilon_0$ 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, what can be said about the potential difference \(V_A - V_B\)?
• Two thin metallic spherical shells are placed concentrically with radii $R_1$ and $R_2$, where $R_1 > R_2$. If the shells carry charges $Q_1$ and $Q_2$ respectively, what is the electric potential at a point located at distance $r$ such that $R_2 < r < R_1$? (Take $k = \frac{1}{4\pi\varepsilon_0}$)
• An alpha particle is made to move through a potential difference of $10^6\ \text{V}$. 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 $K(x) = K_0 + \lambda x$, where $\lambda$ is a constant. How is its capacitance $C$ related to the vacuum capacitance $C_0$?
• 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 →