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 of the following is responsible for the fact that Tennis ball bounces higher at high altitudes than in plains?
[A] Low Gravity
[B] High Gravity
[C] Less dense air
[D] Low atmospheric temperature
Show Answer
Correct Answer: C [ Less dense air ]
Notes:
The rarified air at high altitudes gives less resistance to ball.
2. Any moving object on earth finally comes to rest due to which among the following?
[A] Gravity
[B] Friction
[C] Inertia
[D] Motion
Show Answer
Correct Answer: B [Friction]
Notes:
Friction is the main reason for any object to come to rest. It is the main reason for the stability of the objects on earth.
3. Which among the following would be most commonly affected, if the filament of a electric Bulb is not uniform?
[A] Light
[B] Life
[C] Resistance
[D] None of the above
Show Answer
Correct Answer: B [Life]
Notes:
If the filament of the bulb is affected then the life of the bulb is affected. Filament is very important for the bulb to function.
4. One joule of work is said to be done when__:
[A] a force of 1 dyne causes a displacement of 1 cm.
[B] a force of 1 dyne causes a displacement of 1 m.
[C] a force of 1 N causes a displacement of 1 cm.
[D] a force of 1 N causes a displacement of 1 m.
Show Answer
Correct Answer: D [ a force of 1 N causes a displacement of 1 m.]
Notes:
The joule is the unit of energy in the International System of Units. It is equal to the work done on an object when a force of one Newton acts on that object in the direction of the force’s motion through a distance of one meter. One joule of work is said to be done when a force of 1 N causes a displacement of 1 m.
5. Which of the following lie in the Tetra hertz frequency?
[A] Visible Light and Infra Red
[B] Infra Red and Microwaves
[C] Microwaves and Radio Waves
[D] Visible Light and Ultraviolet light
Show Answer
Correct Answer: B [ Infra Red and Microwaves]
Notes:
The range of the tera hertz radiation frequency is from roughly 0.1 THz to 10 THz. It is higher than the frequency of radio waves and microwaves, but lower than the frequency of infrared light.
6. On heating a pure silicon circular disc with a circular hole at the centre, the diameter of the hole:
[A] will expand
[B] will contract
[C] will remain constant
[D] may expand or contract
Show Answer
Correct Answer: B [ will contract]
Notes:
Pure silicon has a negative coefficient of thermal expansion for temperatures and hence it shows contraction effect.
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. What is the range of masses involved in the study of Physics?
[A] 10-19 kg to 1038 kg
[B] 10-30 kg to 1055kg
[C] 10-30 kg to 1030kg
[D] 10-19 kg to 1055 kg
Show Answer
Correct Answer: B [10-30 kg to 1055kg]
Notes:
The range of masses involved in the study of Physics ranges from 10-30 kg to 1055 kg. 10-30kg is the mass of an electron and 1055 kg is the mass of known observable universe. The range of time scale involved in the study of Physics ranges from 10-22 s to 1018 s. The range of length involved in the study of Physics ranges from 10-14m to 1026 m.
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. Among the following units, which one represents the smallest measurement of length?
[A] Micron
[B] Nanometer
[C] Fermi
[D] Angstrom
Show Answer
Correct Answer: C [Fermi]
Notes:
In the presented choices, the Fermi stands as the smallest unit of length measurement. It is equal to 10^-15 m. Comparatively, 1 Micron equals 10^-6 m, 1 Nanometer equals 10^-9 m, and 1 Angstrom equivalent to 10^-10 m. All these units are commonly used to measure minuscule distances, particularly in the realm of nanotechnology and particle physics. However, the Fermi, named after the esteemed physicist Enrico Fermi, remains the smallest.
