A metallic ring is uniformly charged as shown in the figure. AC and BD are two mutually perpendicular diameters. Electric field due to arc AB to O is ‘E’ magnitude. What would be the magnitude of electric field at ‘O’ due to arc ABC? 
To determine the electric field at point 'O' due to the arc 'ABC', we need to analyze the contribution of each segment of the arc to the net electric field.
Thus, the magnitude of the electric field at 'O' due to the arc 'ABC' is \( \sqrt{2}E \).
To determine the electric field at point \( O \) due to the arc \( ABC \), we start by analyzing the contributions from arcs \( AB \) and \( BC \).
Since these fields are perpendicular to each other and of the same magnitude, we use the Pythagorean theorem to find the resultant electric field:
\(E_{\text{resultant}} = \sqrt{E^2 + E^2} = \sqrt{2E^2} = \sqrt{2}E\)
Thus, the magnitude of the electric field at \( O \) due to the arc \( ABC \) is \(\sqrt{2}E\).
The correct answer is: \(\sqrt{2}E\)
A black body is at a temperature of 2880 K. The energy of radiation emitted by this body with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wien's constant, b = 2.88×106 nm-K. Then,


Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Net dipole moment of a polar linear isotropic dielectric substance is not zero even in the absence of an external electric field. Reason
(R): In absence of an external electric field, the different permanent dipoles of a polar dielectric substance are oriented in random directions.
In the light of the above statements, choose the most appropriate answer from the options given below:
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)