The velocity of upper layer of water in a river is 36 kmh^$$-$$1. Shearing stress between horizontal layers of water is 10^$$-$$3 Nm^$$-$$2. Depth of the river is __________ m. (Co-efficient of viscosity of water is 10^$$-$$2 Pa.s)

A steam engine intakes 50 g of steam at 100$$^\circ$$C per minute and cools it down to 20$$^\circ$$C. If latent heat of vaporization of steam is 540 cal g^$$-$$1, then the heat rejected by the steam engine per minute is __________ $$\times$$ 10³ cal.

(Given : specific heat capacity of water : 1 cal g^$$-$$1 $$^\circ$$C^$$-$$1)

The first overtone frequency of an open organ pipe is equal to the fundamental frequency of a closed organ pipe. If the length of the closed organ pipe is 20 cm. The length of the open organ pipe is _____________ cm.

The equivalent capacitance between points A and B in below shown figure will be __________ $$\mu$$F.