Physics MCQs
Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, NDA, CDS and all one day examinations of India.
1. Which eye defect causes image focus in front of the retina?
[A] Presbyopia
[B] Hypertropia
[C] Myopia
[D] Hyperopia
Show Answer
Correct Answer: C [Myopia]
Notes:
Myopia (short-sightedness) occurs when images are focused in front of the retina, causing distant objects to appear blurry. It is commonly due to an elongated eyeball or excessive corneal curvature. This defect is corrected using concave (diverging) lenses. Hyperopia, by contrast, focuses images behind the retina.
2. Which among the following is true about Total Internal Reflection?
[A] A ray passing from rarer to denser medium and not able to pass to denser medium at an angle greater than critical angle
[B] A ray passing from denser to rarer medium and not able to pass to rarer medium at an angle greater than critical angle
[C] A ray passing from either denser to rarer medium or rarer to denser medium and not able to pass any medium at an angle smaller than critical angle
[D] None of the above
Show Answer
Correct Answer: B [A ray passing from denser to rarer medium and not able to pass to rarer medium at an angle greater than critical angle]
Notes:
A ray passing from denser to rarer medium and not able to pass to rarer medium at an angle greater than critical angle. Critical angle is the angle in which the incident ray is 90 degrees to that of the refracted ray.
3. When light from some sources enters to the earth’s atmosphere, it gets scattered. Which among the following is a reason behind scattering?
[A] Various wavelengths of light
[B] dust, smoke and gas molecules
[C] atmospheric pressure
[D] None of the above
Show Answer
Correct Answer: B [dust, smoke and gas molecules]
Notes:
Scattering of light is the phenomenon in which light rays get deviated from its straight path on striking an obstacle.The scattering of light can be of many reason. Some of them are dust, smoke and gas molecules.
4. What is the normal temperature of human being on Kelvin scale?
[A] 290
[B] 300
[C] 310
[D] 320
Show Answer
Correct Answer: C [310]
Notes:
The normal temperature for a human body is 310 kelvins is 36.85 degrees Celsius. The average normal body temperature is generally accepted as 98.6°F.
5. Which of the following waves is called compression-dilation waves or longitudinal waves?
[A] Primary waves
[B] Secondary waves
[C] Love waves
[D] Rayleigh waves
Show Answer
Correct Answer: A [Primary waves]
Notes:
Primary wave is also called compression-dilation or longitudinal waves. Secondary wave is called transversal wave. Love wave and Rayleigh wave are surface waves. P waves can pass through solid, liquid and gases and are also the fastest among the three main types of waves.
6. Who among the following is credited to work for the unification of electricity, magnetism and optics field of Physics?
[A] James Clerk Maxwell
[B] Michael Faraday
[C] Haris Christian Oersted
[D] Isaac Newton
Show Answer
Correct Answer: A [James Clerk Maxwell]
Notes:
James Clerk Maxwell made the efforts for the unification of electricity, magnetism and optics field of Physics. He showed that light is an electromagnetic wave. James Clerk Maxwell was a Scottish mathematician, physicist and is known best for his mathematical work on electromagnetism and on the behaviour of gases.
7. Who among the following discovered X-rays?
[A] Marie Curie
[B] J.J Thomson
[C] W.C Roentgen
[D] James Chadwick
Show Answer
Correct Answer: C [W.C Roentgen]
Notes:
X-rays were discovered by Wilhelm Conrad Roentgen. W.C Roengten discovered X-Rays while actually working on Cathode rays. X-rays is a form of electromagnetic radiation having a wavelength ranging from 0.01 to 10 nanometers and frequencies in the range 30 petahertz to 30 exahertz. Some Uses of X-Rays: The main use of X-rays is in medicine to check for a broken bone inside body. X-rays can also be used to kill cancer cells. X-rays are used at security checks at airports, railway stations etc. to check customers and baggage. X-rays are also used art historians to see if a picture has been painted on top of an older one. X-ray diffraction is also very important in spectroscopy and as a basis for X-ray crystallography.
8. Nuclear Reactors are based on which of the following phenomenon?
[A] Magnetic confinement of Plasma
[B] Nuclear Fusion
[C] Controlled Nuclear Fission
[D] None of the above
Show Answer
Correct Answer: C [Controlled Nuclear Fission]
Notes:
Nuclear Reactors uses Controlled Nuclear Fission to generate electricity. A nuclear reactor splits the atoms of nuclear fuel (eg. uranium) to generate energy to turn water into steam to drive turbine generators. Nuclear fission is the splitting of a heavy nucleus into two lighter ones. Fission was discovered in 1938 by the German scientists Otto Hahn, Lise Meitner, and Fritz Strassmann.
9. Which of these branches of Physics deal with heat and temperature and their relation to energy and work?
[A] Geophysics
[B] Mechanics
[C] Atomic Physics
[D] Thermodynamics
Show Answer
Correct Answer: D [Thermodynamics]
Notes:
Thermodynamics is that branch of physics which deals with heat and temperature and their relation to energy (such as mechanical, electrical, or chemical energy) and work. The behaviour of these quantities is governed by the four laws of thermodynamics
10. kg m2is the unit of which of the following physical quantities?
[A] Linear Momentum
[B] Angular Momentum
[C] Angular Impulse
[D] Moment of Inertia
Show Answer
Correct Answer: D [ Moment of Inertia ]
Notes:
kg m2is the unit of Moment of Inertia. The moment of inertia is a physical quantity which describes how easily a body can be rotated about a given axis. It is a rotational analogue of mass. Moment of Inertia = mass x (radius of gyration)2
