If $$\mathrm{I}_0$$ is the intensity of the principal maximum in the single slit diffraction pattern, then what will be the intensity when the slit width is doubled?

Two circular coils made from same wire but radius of $$1^{\text {st }}$$ coil is twice that of $$2^{\text {nd }}$$ coil. If magnetic field at their centres is same then ratio of potential difference applied across them is ($$1^{\text {st }}$$ to $$2^{\text {nd }}$$ coil)

Five current carrying conductors meet at point $$\mathrm{P}$$. What is the magnitude and direction of the current in conductor $$\mathrm{PQ}$$?

Water rises in a capillary tube of radius '$$r$$' upto a height '$$h$$'. The mass of water in a capillary is '$$m$$'. The mass of water that will rise in a capillary tube of radius $$\frac{'r'}{3}$$ will be