The outer rail of a curved railway track is generally raised over the inner. Why ?

The two rails of a railway track, insulated from each other and the ground, are connected to a milli voltmeter. What is the reading of the milli voltmeter when a train travels at a speed of 180 km//hours along the track, given that the vertical components of earth's magnitic field is 0.2xx10^(_4) weber//m^(2) & the rails are separated by 1 meter?

The radius of curvature of a railway track at a place where the train is moving at a speed of 72 km h^-1 is 625 m.The distance between the rails is 1.5 m.Find the angle and the elevation of the outer rail so that there may be no side pressure on the rails. (g=9.8 m s^(-2)) .

Automobile tyres have generally irregular projections over their surfaces. Why?

The radius of curvature of a railway line at a place is 40000m.the train is running at 20 m s^-1 .the distance between the two rails is 1.5 m.Find the elevation of the outer rail over the inner one so that the train may be able to run safely.

Why is a curved road banked on the outer side?/

A spherical capacitor has an inner sphere of radius 12 cm and an outer sphere of radius 13 cm. The outer sphere is earthed and the inner sphere is given a charge of 2.5 muC . The space between the concentric spheres is filled with a liquid of dielectric constant 32. Compare the capacitance of this capacitor with that of an isolated sphere of radius 12 cm. Explain why the latter is much smaller.

Answer the following :- Comets move around the sun in highly elliptical orbits. The gravitational force on the comet due to the sun is not normal to the comet’s velocity in general. Yet the work done by the gravitational force over every complete orbit of the comet is zero. Why ?