A thin equi-convex lens is made of glass of refractive index 1.5 and its focal length is 0.2 m. If it acts as a concave lens of focal length 0.5 cm when dipped in a liquid, the refractive index of the liquid is
A moving coil galvanometer has a resistance of 60 $$\Omega$$ and it indicates full deflection on passing a current of 4.5 mA. A voltmeter is made using this galvanometer and a 4.5 k$$\Omega$$ resistance. The maximum voltage, that can be measured using this voltmeter, will be close to
The combination of the gates shown in following figure yields
A vessel contains one mole of O2 gas (molar mass 32) at a temperature T. The pressure of the gas is p. An identical vessel containing one mole of He gas (molar mass 4) at a temperature 2T has a pressure of