The electric potential at the surface of an atomic nucleus \( (z = 50) \) of radius \( 9 \times 10^{-13} \) cm is \(\_\_\_\_\_\_\_ \)\(\times 10^{6} V\).
To find the electric potential \( V \) at the surface of an atomic nucleus with atomic number \( z = 50 \) and radius \( r = 9 \times 10^{-13} \text{ cm} \), we use the formula for the electric potential due to a point charge:
\( V = \frac{k \cdot q}{r} \)
where \( k = 8.99 \times 10^{9} \, \text{N m}^2/\text{C}^2 \) is the Coulomb's constant, and \( q = z \cdot e \) is the total charge of the nucleus with \( e = 1.6 \times 10^{-19} \, \text{C} \). Thus, \( q = 50 \cdot 1.6 \times 10^{-19} \, \text{C} = 8 \times 10^{-18} \, \text{C} \).
Substituting the known values into the formula:
\( V = \frac{8.99 \times 10^{9} \cdot 8 \times 10^{-18}}{9 \times 10^{-15}} \)
Simplifying the expression:
\( V = \frac{71.92 \times 10^{-9}}{9 \times 10^{-15}} = 7.991 \times 10^{6} \, \text{V} \)
The calculated potential is \( 7.991 \times 10^{6} \, \text{V} \), which is approximately \( 8 \times 10^{6} \, \text{V} \).
The electric potential at the surface of a nucleus is given by:
\(V = \frac{kQ}{R} = \frac{kZe}{R},\)
where:
- \(k = 9 \times 10^9 \, \text{Nm}^2/\text{C}^2\),
- \(Z = 50\),
- \(e = 1.6 \times 10^{-19} \, \text{C}\),
- \(R = 9 \times 10^{-13} \, \text{cm} = 9 \times 10^{-15} \, \text{m}\).
Substituting the values:
\(V = \frac{9 \times 10^9 \times 50 \times 1.6 \times 10^{-19}}{9 \times 10^{-15}}\)
Simplify:
\(V = 8 \times 10^6 \, \text{V}.\)
The Correct answer is: 8
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,

In a nuclear fission reaction of an isotope of mass \( M \), three similar daughter nuclei of the same mass are formed. The speed of a daughter nuclei in terms of mass defect \( \Delta M \) will be:
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 : \(A_2 \rightleftharpoons 2A\)