A black body is at a temperature of 5760 K. The energy of radiation emitted by the body at wavelength 250 nm is U₁, at wavelength 500 nm is U₂ and that at 1000 nm is U₃. Wien's constant, b = 2.88 $$ \times $$ 10⁶ nm K. Which of the following is correct ?

Water rises to a height h in capillary tube. If the length of capillary tube above the surface of water is made less than h, then

The value of coefficient of volume expansion of glycerin is 5 $$ \times $$ 10^$$-$$4 K^$$-$$1. The fractional change in the density of glycerin for a rise of 40^oC in its temperature, is

The cylindrical tube of a spray pump has radius R, one end of which has n fine holes, each of radius r. If the speed of the liquid in the tube is V, the speed of the ejection of the liquid through the holes is