General Physics

Integrated circuits are compact, and cheap and fast and more efficient than conventional circuits, and hence they are preferred over them.

The heat content of anthracite ranges from 22 to 28 million Btu per short ton (26 to 33 MJ/kg) on a moist, mineral-matter-free basis. Anthracite (“coallike”) is a hard, compact variety of mineral coal that has a high luster.

Instability due to negative resistance of a tunnel diode is its drawback.

Brake force, also known as Brake Power, is a measure of braking power of a vehicle. Suppose a car whose mass is ‘x’ and is braked from a speed of y km/hr to come to halt at a uniform retardation in z min. If the speed of the car is doubled in the same distance, then the braking force required to stop the car is four times the original speed i.e. ‘4v’. Note that all the parameters remain to be same.

On the surface of the Earth, the escape velocity is about 11.2 kilometers per second (~6.96 mi/s), which is approximately 34 times the speed of sound (Mach 34) and several times the muzzle velocity of a rifle bullet (up to 1.7 km/s). However, at 9,000 km altitude in “space”, it is slightly less than 7.1 km/s. In physics, escape velocity is the speed at which the kinetic energy plus the gravitational potential energy of an object is zero.

In the late of 17th century British scientist Isaac Newton studied cooling of bodies. Experiments showed that the cooling rate is approximately proportional to the difference of temperatures between the heated body and the environment. This fact can be written as the differential relation :

Lightning heats the surrounding air to 30000 deg Cent.

Batholith is the biggest of the intrusive igneous rocks. Stope is not an intrusive igneous body. It is related to mining.

The instrument for measuring intensity of earthquakes is called Seismograph.

An instrument that records earthquakes is Seismograph.

To prevent damage from lightning, lightning conductors are used on tall structures. The lightning conductor should be made of a good conductor like copper with sharp-pointed edges.

A small gap is left at the joints of rails in a railway track to avoid the tracks being distorted due to seasonal temperature variation.

Water in pipes freeze in cold countries. Due to the anomalous expansion of water, it expands instead of contacting when there is a fall in temperature below 4°c. So, the water pipes burst due to the excess space consumed by the ice after freezing.

Water in pipes freeze in cold countries. Due to the anomalous expansion of water, it expands instead of contacting when there is a fall in temperature below 4°c. So, the water pipes burst due to the excess space consumed by the ice after freezing.

Railway tracks are banked at the curves so that the necessary centripetal force may be obtained from the horizontal component of the reaction on the train.