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. The ideal fluid which is a hypothetical fluid should contain _______?
[A] Zero Viscosity Only
[B] Zero Compressibility Only
[C] Zero Viscosity & Zero Compressibility
[D] None of the above
Show Answer
Correct Answer: C [Zero Viscosity & Zero Compressibility]
Notes:
An ideal fluid hypothetical fluid should contain Zero Viscosity & Zero Compressibility. Almost all fluids will not have zero viscosity and zero compressibility.
3. Mach number is a measure of which of the following?
[A] Speed
[B] Heat Transfer
[C] Static Pressure
[D] Volume
Show Answer
Correct Answer: A [Speed]
Notes:
Mach number refers to the ratio of the velocity of a fluid to the velocity of sound in that fluid, named after Ernst Mach (1838–1916), an Austrian physicist and philosopher. Speed of sound is Mach 1 speed.
4. The term “Isopycnic” is most closely defined by which among the following?
[A] Two places with same atmospheric pressure
[B] Two liquids with same viscosity
[C] Two liquids with same density
[D] Two places with same temperature
Show Answer
Correct Answer: C [Two liquids with same density]
Notes:
The term “Isopycnic” refers to two substances having the same density. It is derived from the Greek words “iso,” meaning equal, and “pycnos,” meaning dense. In scientific contexts, isopycnic conditions are often used in centrifugation techniques to separate particles based on their density, such as in the purification of DNA or proteins.
5. Which among the following is measured by an Odometer?
[A] Pressure
[B] Height
[C] Distance
[D] Velocity
Show Answer
Correct Answer: C [Distance]
Notes:
An odometer is an instrument used for measuring the distance. It measures distance traveled by a vehicle such as a bicycle or car. The device may be electronic, mechanical, or a combination of the two.
6. A long Rail (approximately 700 meters) made up of steel is struck to produce a sound. The person standing on the other end of the rail would hear in which among the following pattern?
[A] He listens the sound waves once propagated via steel
[B] He listens the sound waves once propagated via air
[C] He listens the sound waves twice, first propagated via steel and second propagated via air
[D] He listens the sound waves twice, first propagated via air and second propagated via steel
Show Answer
Correct Answer: C [He listens the sound waves twice, first propagated via steel and second propagated via air]
Notes:
The correct answer is that the person hears the sound waves twice: first via steel and then via air. Sound travels faster in solids than in gases. in steel, it travels at about 5,960 m/s, while in air, it travels at approximately 343 m/s. Given the long distance of 700 meters, the sound will reach the person through the steel rail first, followed by the sound traveling through the air. This phenomenon illustrates the differences in sound propagation speeds in different media.
7. If a moving body turns its speed to 1.5 times, its kinetic energy __:
[A] will become 1.5 times
[B] will become 3 times
[C] will become 2.25 times
[D] will become 6 times
Show Answer
Correct Answer: C [ will become 2.25 times]
Notes:
Kinetic Energy is a product of half the Mass times Velocity Squared. When the velocity is doubled, the Kinetic energy would go up four times. If velocity is tripled, kinetic energy would go up nine times. If velocity is increased by 1.5 times the Kinetic energy would go up by 1.5×1.5=2.25 times.
8. Who gave the Theory of Relativity?
[A] Isaac Newton
[B] Archimedes
[C] Albert Einstein
[D] Galileo Galilei
Show Answer
Correct Answer: C [Albert Einstein]
Notes:
Albert Einstein was the founder of Theory of Relativity. According to Einstein’s theory, mass m is equivalent to energy E given by the relation E = mc^2 where c is speed of light in vacuum. Albert Einstein was awarded the 1921 Nobel Prize in Physics for his contribution to the field of Theoretical Physics.
9. 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.
10. Which of the following pairs represent two scalar quantities?
[A] Mass, Acceleration
[B] Temperature, Torque
[C] Distance, Speed
[D] Gravitational Intensity, Work
Show Answer
Correct Answer: C [Distance, Speed]
Notes:
The physical quantities which have only magnitude and no direction are called as Scalar quantities. Some examples of Scalar quantities: Work, Mass, Temperature, Distance, Speed.
