The number of turns in the primary and the secondary of a transformer are 1000 and 3000 , respectively. If $$80 \mathrm{~V} \mathrm{~AC}$$ is applied to the primary coil of the transformer, then the potential difference per turn of the secondary coil would be

The ratio of magnetic field at the centre of the current carrying circular loop and magnetic moment is $$X$$. When both the current and radius are doubled, then the ratio will be

Light of wavelength $$5000 \mathop A\limits^o$$ is incident normally on a slit. The first minimum of the diffraction pattern is observed to lie at a distance of $$5 \mathrm{~mm}$$ from the central maximum on a screen placed at a distance of $$2 \mathrm{~m}$$ from the slit. The width of the slit is

When two tuning forks are sounded together, 5 beats per second are heard. One of the forks is in unison with $$0.97 \mathrm{~m}$$ length of sonometer wire and the other is in unison with $$0.96 \mathrm{~m}$$ length of the same wire. The frequencies of the two tuning forks are