The vernier scale used for measurement has a positive zero error of 0.2 mm. If while taking a measurement it was noted that '0' on the vernier scale lies between 8.5 cm and 8.6 cm, vernier coincidence is 6, then the correct value of measurement is ___________ cm. (least count = 0.01 cm)

A current of 10A exists in a wire of cross-sectional area of 5 mm² with a drift velocity of 2 $$\times$$ 10^$$-$$3 ms^$$-$$1. The number of free electrons in each cubic meter of the wire is ___________.

The output of the given combination gates represents :

Which level of the single ionized carbon has the same energy as the ground state energy of hydrogen atom?