Physics — Part 2 MCQs with Explanations

Sound travels fastest through solids. This is because molecules in a solid medium are much closer together than those in a liquid or gas, allowing sound waves to travel more quickly through it. In fact, sound waves travel over 17 times faster through steel than through air.

The raise of oil up the wick in a lamp is an example of capillary action where adhesive forces are greater than cohesive forces.

By definition, superconductors are substances which display zero electrical resistance when a current is supplied, and are able to propagate such a current in a circuit indefinitely.

Light travels at the fastest speed in Vacuum.

When a fast moving train takes a curved path, it tends to move away tangentially off the track. In order to prevent this, the curved tracks are banked on the outside to produce the necessary centripetal force required to keep the train moving in a curved path.

Metals are good conductor of heat.

3.3 km, 0.30 km.

Intensity of sound at a point is inversely proportional to square of its distance from the source.

Of the four locations mentioned below the highest inside temperature will be attained in the pressure cooker operated with the pressure valve open at a place in a valley below sea level.

Radio telescopes are better than optical telescopes because they can detect faint galaxies which no optical telescope can, they can work even in cloudy conditions and they can work during the day and night.

Light Emitting Diodes (LED) is used in fancy electronic devices such as toys emit visible light.

Moment of inertia and moment of a force does not have identical dimension.

Mercury has greater visibility than water.

The optical fibre is a device which works on the principle of total internal reflection by which light signals can be transmitted from one place to another with a negligible loss of energy. Characteristics of Optical Fibre: It has a large bandwidth.

Light from the nearest star reaches the earth in 4.2 years. The closest star to Earth are three stars in the Alpha Centauri system.

Vehicles that fly at supersonic speeds are flying faster than the speed of sound.

Mach number is used in connection with the speed of aircraft.

In this case air blown by the fan will try to push the sail boat in a certain direction. But at the same time due to Newton's third law of motion the fan will experience a force due to the air blown in a direction opposite to the direction in which the sail boat will experience the force due to the blown air. So, as a whole the system will be at rest and it will not move.

A rainbow is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the sun.

They are single to naked eye because they are far from us. But, if we see with telescope We can observe that there are two or double stars.

ML 2 T -2 is the dimensional formula for couple acting on a body.

Solar eclipse will take place when the moon is between the sun and the earth.

Isotopes are atoms of the same element that have different numbers of neutrons but the same number of protons and electrons. The difference in the number of neutrons between the various isotopes of an element means that the various isotopes have different masses.

One watt-hour is equivalent to 3.6 x 10 3 J

The Nobel Prize in Physics 1930 was awarded to Sir Chandrasekhara Venkata Raman "for his work on the scattering of light and for the discovery of the effect named after him."

In electrical industries mica is used as a raw material.

Radiocarbon dating involves determining the age of an ancient fossil or specimen by measuring its carbon-14 content. Carbon-14, or radiocarbon, is a naturally occurring radioactive isotope that forms when cosmic rays in the upper atmosphere strike nitrogen molecules, which then oxidize to become carbon dioxide.

Angular momentum is a vector quantity.

Large astronomical telescopes always use as objective combination of lenses.

If we connect many appliances to the same socket, requirement of current for that socket will increase, the wire connected to that socket will have to supply more current, that may exceed its current rating and can damage it.

Refraction and internal reflection are responsible for this physical phenomena.

Natural radioactivity was discovered by Henri Becquerel.

Planets are non-luminous heavenly bodies.

One nanometer is equal to 10 -9 m.

Mica is used in electrical appliances such as electric iron because mica is a good conductor of heat but a bad conductor of electricity.

When a body slides (moves with all its surface area in contact) over another body, the resistance faced is due to sliding friction. Hence rolling friction is less than the sliding friction. Thus it is easier to roll a barrel full of coal tar than to pull it.

The minimum number of vectors of unequal magnitude required to produce zero resultant is three.

Intensity of sound has an object existence.

With vertical, the relative velocity will be inclined and appear to be coming from east.So the rain will appear to be coming from east.

Coolidge tube is used to produce X-ray.