| List-I | List-II |
|---|---|
| (A) Kinetic energy of planet | \(- \frac{GMm}{a}\) |
| (B) Gravitational Potential energy of Sun-planet system | \(- \frac{GMm}{2a}\) |
| (C) Total mechanical energy of planet | \(\frac{GM}{r}\) |
| (D) Escape energy at the surface of planet for unit mass object | \(- \frac{GMm}{2a}\) |
The kinetic energy (KE) of a planet is given by:
\[ \text{KE} = \frac{1}{2} mv^2 = \frac{GMm}{2a} \]
The gravitational potential energy (PE) of the Sun-planet system is:
\[ \text{PE} = -\frac{GMm}{a} \]
The total mechanical energy (TE) of the planet is:
\[ \text{TE} = \text{KE} + \text{PE} = -\frac{GMm}{2a} \]
Escape energy at the surface of the planet for a unit mass object is given by:
\[ \text{Escape Energy} = \frac{Gm}{r} \]
Step 1: Recall the relevant formulas
For a planet of mass \( m \) orbiting the Sun of mass \( M \) at a distance \( a \):
Step 2: Match each quantity correctly
| List-I | List-II |
|---|---|
| (A) Kinetic energy of planet | \( +\dfrac{GMm}{2a} \) |
| (B) Gravitational potential energy of Sun–planet system | \( -\dfrac{GMm}{a} \) |
| (C) Total mechanical energy of planet | \( -\dfrac{GMm}{2a} \) |
| (D) Escape energy at the surface of planet for unit mass object | \( +\dfrac{GM}{r} \) |
Step 3: Final correspondence
\[ (A) - II, \quad (B) - I, \quad (C) - IV, \quad (D) - III \]
Final answer
(A) – II, (B) – I, (C) – IV, (D) – III
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,

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 : \(A_2 \rightleftharpoons 2A\)