Physics MCQs

Notes:
The momentum of a particle is given by the equation, P = mv, where P is the momentum of the particle, m is the mass of the particle, and v is the velocity of the particle. The kinetic energy of a particle is given by the equation, KE = . mv2. So, if momentum is doubled, kinetic energy increases four times.

Notes:
In photography, shutter speed or exposure time is the effective length of time a camera’s shutter is open to let light enter into camera . The total exposure is proportional to this exposure time, or duration of light reaching the film or image sensor. The correct exposure for a particular object depends on the brightness of the object to be photographed.

Notes:
The human eye is sensible to light having wavelength roughly between 400 nm and 700 nm. When illumination is enough (in daylight) the maximum sensitivity is in the green region at 555 nm. However, human eyes are the most sensitive to yellow colour light.

Notes:
The twinkling of primarily caused by atmospheric multiple refraction of light. The early sun rise and late sunset by 2 minutes each respectively is also because of atmospheric refraction of light. The appearing of the sun to be red at dawn and dusk is primarily because of scattering of light than refraction of hight. Red light is scattered the least among all colour of light present in the visible spectrum of white light.

Notes:
Convex mirror is also known as diverging mirror as this mirror diverges light when they strike on its reflecting surface. Virtual, erect and diminished images are always formed with convex mirrors, irrespective of the distance between the object and the mirror. Apart from other applications, convex mirror is mostly used as rear view mirror in vehicles.

Notes:
Angle of incidence is the angle between an incident ray and the normal. Angle of refraction is the angle between a refracted ray and the normal. When the angle of refraction is equal to 90°, the angle of incidence is called the critical angle. In this case, the light ray goes from denser to rarer medium.

Notes:
The tesla (symbol T) is the SI derived unit used to measure magnetic fields. Tesla can be measured in different ways; for example, one tesla is equal to one Weber per square metre. The tesla was first defined in 1960 by the General Conference on Weights and Measures (CGPM). It was named in honour of the physicist, electrical engineer, and inventor, Nikola Tesla.

Notes:
The SI unit of magnetic flux is the Weber (Wb) (in derived units: volt-seconds). It is the magnetic flux that, linking a circuit of one turn, would produce in it an electromotive force of 1 volt if it were reduced to zero at a uniform rate in 1 second. The CGS unit of magnetic flux is Maxwell.

Notes:
In physics and chemistry, the Lyman series is a hydrogen spectral series of transitions and resulting ultraviolet emission lines of the hydrogen atom as an electron goes from n > 2 to n = 1 (where n is the principal quantum number) the lowest energy level of the electron. The first line in the spectrum of the Lyman series was discovered in 1906 by Theodore Lyman, while studying the ultraviolet spectrum of electrically excited hydrogen gas.

Notes:
A semiconductor is a substance with electrical conductivity intermediate between that of an insulator and a conductor. Elemental semiconductors include antimony, arsenic, boron, carbon, germanium, selenium, silicon, sulfur, and tellurium. Silicon is the best-known of these, forming the basis of most integrated circuits (ICs).