What are electromagnetic waves? Explain two characteristics of these waves.
Two characteristics of electromagnetic waves are:
The path of scattered \( \alpha \)-particle is:
The maximum focal length of convex lens is for:
The power consumed in alternating current in a circuit containing only a capacitor will be:
The unit of magnetic field is
If the radius of the nucleus of \(^{13} \text{Al}^{27}\) is 3.6 fermi, then the radius of the nucleus of \(^{52} \text{Te}^{125}\) is:
What is the main difference between paramagnetic and ferromagnetic substances?
A charge \( Q \) is distributed over two concentric hollow spheres of radii \( r \) and \( R \) (\( R>r \)) such that their surface charge densities are equal. Find the electric potential at their common center.
Show that the circumference of the orbit of an electron revolving in the \( n \)-th orbit is equal to \( n\lambda \) with the help of Bohr's quantum theory. Also, show the emission and absorption spectral lines between energy levels \( n = 1 \) and \( n = 3 \) of hydrogen atom.