A copper tube (length, 3.0 m, inner diameter, 1.5 cm, outer diameter, 1.7 cm) passes through a vat of rapidly circulating water maintained at `20^@C`. Live steam at `100^@C` passes through the tube. What is the heat flow rate from the steam into the vat? For copper, kT = 1.0 cal/s·cm·°C.

An electric flux of -6xx10^3Nm^2C^-1 passes through a spherical gaussian surface of radius 10 cm due to a point charge placed at the centre. What is the charge enclosed by the gaussian surface.

A hollow copper tube of 5 m length has got external diameter equal to 10 cm and the walls are 5 mm thick . If specific resistance of copper is 1.7xx10^(-8) ohm meter. Calculate the resistance of the tube.

A brass rod of length 50 cm and diameter 3.00 mm is joined to a steel rod of the same length and diameter. What is the change in length of the combined rod at 250^@C , if the original lengths are at 40.0^@C ? Is there a 'thermal stress' developed at the junction? The ends of the rod are free to expand coefficent of linear expansion of brass = 2.0 xx 10^-5 ^@C^-1 , steel = 1.2 xx 10^-5 ^@C^-1 ).

The thicknes of a metallic tube is 1 cm and the inner diameter of the tube is 12 cm. Find the mass of 1 m long tube, if the density of the metal be 7.8 g//cm^3 .

A cylinder of diameter exactly 1 cm at 30^@C is to be slided into a hole in a steel plate. The hole has a diameter of 0.99970 cm at 30^@C . To what temperature must the plate be heated? For steel alpha = 1.1 xx 10^-5 ^@C^-1

A solenoid 1.5 m long and 0.4 cm in diameter possesses 10 turns per cm length. A current of 5 A falls through it. The magnetic field at the axis inside the solenoid is

Light of wavelength 5.4 xx 10^(-5)cm passes through a silt 0.12 cm wide and forms a diffraction pattern on a screen 2.7 m away. What is the width of the central maxima?

A uniform magnetic field of 1.5 T exists in a cylindrical region of radius10.0 cm, its direction parallel to the axis along east to west. A wire carrying current of 7.0 A in the north to south direction passes through this region. What is the magnitude and direction of the force on the wire if, the wire intersects the axis.

A uniform magnetic field of 1.5 T exists in a cylindrical region of radius10.0 cm, its direction parallel to the axis along east to west. A wire carrying current of 7.0 A in the north to south direction passes through this region. What is the magnitude and direction of the force on the wire if, the wire in the N-S direction is lowered from the axis by a distance of 6.0 cm?