COMEDK · Physics · 17. Electrostatics

Dielectric constant of a metal is

A zero
B infinite
C finite
D unpredictable

Verified Solution

Answer & Solution

Correct Answer

(B) infinite

Step-by-step Solution

Detailed explanation

Permittivity of metal is very high, so its dielectric constant is infinite.

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

Same subject

A uniformly charged solid sphere of radius \(\mathrm{R}\) has potential \(\mathrm{V}_0\) (measured with respect to infinity) on its surface. For this sphere the equipotential surfaces with potentials \(\dfrac{3 \mathrm{~V}_0}{2}, \dfrac{\mathrm{V}_0}{1}, \dfrac{3 \mathrm{~V}_0}{4}\) and \(\dfrac{\mathrm{V}_0}{4}\) have radius \(\mathrm{R}_1, \mathrm{R}_2, \mathrm{R}_3\) and \(\mathrm{R}_4\) and respectively, then

COMEDK 2024 Hard
The temperature at which centigrade and Fahrenheit scales give the same reading, is

COMEDK 2015 Easy
Emission of electrons from a metal plate illuminated with monochromatic electromagnetic radiation will always take place provided

COMEDK 2025 Easy
The time dependence of a physical quantity P is give by \(\mathrm{P=P}_0 \exp \left(-\alpha t^2\right)\) where \(\alpha\) is a constant and \(t\) is time. The constant \(\alpha\) will

COMEDK 2023 Easy
Carnot cycle of an engine is given below

Total work done by the gas in one cycle is

COMEDK 2021 Hard
The average kinetic energy of a molecule in air at room temperature of \(20^{\circ} \mathrm{C}\)

COMEDK 2022 Easy

Explore more questions on app

From COMEDK

A horizontal overhead power line carries a current of \(90 \mathrm{~A}\) in East to West direction. What is the magnitude and direction of the magnetic field due to the current, \(1.5 \mathrm{~m}\) below the line?

COMEDK 2020 Medium
Two statements, One Assertion [A ] and the other Reason [ R ] are given. Identify the correct option Assertion [A]: The decreasing order of the acidic character of the following is \(\mathrm{B}>\mathrm{D}>\mathrm{A}>\mathrm{C}\)

Reason \([\mathrm{R}]\) : Fluorine has larger -I effect than Cl and Br .

COMEDK 2025 Medium
In which of the following complex ion, the central metal ion is in a state of \(s p^{3} d^{2}\) hybridisation?

COMEDK 2018 Medium
An electric bulb is rated at 220 V and 100 W . Power consumed by bulb when operated at 110 V will be

COMEDK 2024 Easy
The function \(f: X \rightarrow Y\) defined by \(f(x)=\sin x\) is one-one but not onto if \(X\) and \(Y\) are respectively, is equal to

COMEDK 2016 Easy
A beam of parallel rays is brought to focus by a plano-convex lens. A thin concave lens of the same focal length is joined to the first lens. The effect of this is

COMEDK 2013 Easy

Explore more questions on app