On dry road, the maximum speed of a vehicle along a circular path is '$$V$$'. When the road becomes wet, maximum speed becomes $$\frac{\mathrm{V}}{2}$$. If coefficient of friction of dry road is '$$\mu$$' then that of wet road is

A wire of length $$3 \mathrm{~m}$$ connected in the left gap of a meter-bridge balances $$8 \Omega$$ resistance in the right gap at a point, which divides the bridge wire in the ratio $$3: 2$$. The length of the wire corresponding to resistance of $$1 \Omega$$ is

By adding soluble impurity in a liquid, angle of contact

For a common emitter configuration, if '$$\alpha$$' and '$$\beta$$' have their usual meanings, the incorrect relation between '$$\alpha$$' and '$$\beta$$' is