A double convex air bubble in water behaves as

Three liquids have same surface tension and densities $$\rho_1, \rho_2$$, and $$\rho_3\left(\rho_1>\rho_2>\rho_3\right)$$. In three identical capillaries rise of liquid is same. The corresponding angles of contact $$\theta_1, \theta_2$$ and $$\theta_3$$ are related as

If a lighter body of mass '$$\mathrm{M}_1$$' and velocity '$$\mathrm{V}_1$$' and a heavy body (mass $$M_2$$ and velocity $$V_2$$ ) have the same kinetic energy then

Electron of mass '$$\mathrm{m}$$' and charge '$$\mathrm{q}$$' is travelling with speed '$$v$$' along a circular path of radius '$$R$$', at right angles to a uniform magnetic field of intensity '$$B$$'. If the speed of the electron is halved and the magnetic field is doubled, the resulting path would have radius