For questions involving assertions and reasons, analyze each statement indepen dently. Recall the relevant formulas and concepts to determine the truth or false hood of each statement.
Both \(A\) and \(R\) are true and \(R\)is the correct explanation of \(A\)
Both \(A\) and \(R\) are true but \(R\) is not the correct explanation of \(A\)
A is true but \(R\) is false
A is false but \(R\) is true
Step 1: Analyze Assertion A
The potential of a conducting sphere (solid or hollow) is given by: \[ V = \frac{KQ}{R} \] where \(V\) is the potential, \(K\) is a constant, \(Q\) is the charge, and \(R\) is the radius.
If two spheres have the same potential (\(V_1 = V_2\)) and the same radius (\(R_1 = R_2\)), then: \[ \frac{KQ_1}{R_1} = \frac{KQ_2}{R_2} \] Since \(R_1 = R_2\), it follows that \(Q_1 = Q_2\). Therefore, the assertion that the solid sphere will have a lower charge is false. The charges must be equal.
Step 2: Analyze Reason R
The capacitance of a spherical conductor is given by: \[ C = 4\pi \epsilon_0 R \] where \(C\) is the capacitance, \(\epsilon_0\) is the permittivity of free space, and \(R\) is the radius. This shows that the capacitance of a metallic sphere depends only on its radius. Therefore, the reason is true.
Conclusion: Assertion A is false, but Reason R is true. Therefore, the correct option is (4).
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,


A particle of mass \( m \) and charge \( q \) is fastened to one end \( A \) of a massless string having equilibrium length \( l \), whose other end is fixed at point \( O \). The whole system is placed on a frictionless horizontal plane and is initially at rest. If a uniform electric field is switched on along the direction as shown in the figure, then the speed of the particle when it crosses the x-axis is:
As shown below, bob A of a pendulum having massless string of length \( R \) is released from \( 60^\circ \) to the vertical. It hits another bob B of half the mass that is at rest on a frictionless table in the center. Assuming elastic collision, the magnitude of the velocity of bob A after the collision will be (take \( g \) as acceleration due to gravity):

The magnitude of heat exchanged by a system for the given cyclic process ABC (as shown in the figure) is (in SI units):


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 : \(A_2 \rightleftharpoons 2A\)
It is the property of subatomic particles that experiences a force when put in an electric and magnetic field.
It is a property associated with each point in space when charge is present in any form. The magnitude and direction of the electric field are expressed by E, called electric field strength or electric field intensity.
Electric charges are of two types: Positive and Negative. It is commonly carried by charge carriers protons and electrons.
Various properties of charge include the following :-
Two kinds of electric charges are there :-
When there is an identical number of positive and negative charges, the negative and positive charges would cancel out each other and the object would become neutral.