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. Speed of sound is maximum in which among the following?
[A] Solids
[B] liquids
[C] Gases
[D] Vaccum
Show Answer
Correct Answer: A [Solids]
Notes:
The speed of sound decreases when we go from solid to gaseous state.
3. Which among the following orbits are more prone to harms of space debris or space Junk in comparison to others?
[A] Polar Sun Synchronous Orbit
[B] Low Earth Orbit
[C] Geosynchronous orbit
[D] Geostationary Orbit
Show Answer
Correct Answer: D [ Geostationary Orbit]
Notes:
Low Earth Orbit (LEO) is more prone to space debris or space junk. This is because space debris is more concentrated in orbits closer to Earth. Most debris is within 2,000 km (1,200 miles) of Earth’s surface.
Space debris orbits the Earth at tremendous speeds, about 15,700 miles per hour (25,265 kph) in low Earth orbit. In the event of a collision, it could cause significant damage to a satellite or spacecraft.
Experts are concerned about the amount of space debris in regions that are too high to benefit from the cleansing effects of Earth’s atmosphere. They believe that if there is too much space junk in orbit, it could result in a chain reaction where more and more objects collide and create new space junk.
4. Who among the following gave the Uncertainity principle?
[A] R.A Milkman
[B] Ernset Rutherford
[C] S.N Bose
[D] Werner Heisenberg
Show Answer
Correct Answer: D [Werner Heisenberg]
Notes:
Werner Heisenberg, a german Physicist, discovered the Uncertainity principle. As per the uncertainty principle, we cannot measure the position (x) and the momentum (p) of a particle with absolute precision. The more accurately we know one of these values, the less accurately we know the other. It represnts the effects of wave-particle duality on the properties of subatomic objects.
5. 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.
6. Which of the these physical quantities is a vector quantity?
[A] Temperature
[B] Speed
[C] Gravitational Intensity
[D] Work
Show Answer
Correct Answer: C [Gravitational Intensity]
Notes:
The physical quantities which have both magnitude and direction are called as Vector quantities. Some examples of Vector quantities: Acceleration, Velocity, Torque, Displacement, Gravitational Intensity, Force.
7. Which of the following conditions is true for two vectors to be collinear?
[A] Equal magnitude
[B] Same Direction
[C] Acting along the parallel straight lines
[D] Both a and c
Show Answer
Correct Answer: C [Acting along the parallel straight lines]
Notes:
Two vectors are said to be collinear if they are acting along the parallel straight lines. The collinear vectors may or may not have equal magnitude.
8. A projectile will achieve maximum horizontal range at which angle?
[A] 90°
[B] 60°
[C] 45°
[D] 30°
Show Answer
Correct Answer: C [45°]
Notes:
A projectile will achieve maximum horizontal range when it is projected at an angle of 45°. This concept of maximum horizontal range is used by athletes in long jump, javelin throw, cricket ball throw etc
9. What happens to the velocity of a light body when it undergoes an elastic collision in one dimension with a very heavy body at rest?
[A] its velocity becomes twice
[B] it rebounds with twice of its own velocity
[C] it rebounds with its own velocity
[D] it stops and comes to rest
Show Answer
Correct Answer: C [it rebounds with its own velocity]
Notes:
A light body rebounds with its own velocity when it undergoes an elastic collision in one dimension with a very heavy body at rest. Note: The heavy body continues to be in rest in this case
10. Which of the following laws state that the orbits of the planets are ellipses, with the Sun at one focus of the ellipse?
[A] Kepler’s First law
[B] Kepler’s Second law
[C] Kepler’s Third law
[D] None of the above
Show Answer
Correct Answer: A [Kepler’s First law]
Notes:
Kepler’s First law: It is also known as law of orbits. It states that every planet revolves around the sun in an elliptical orbit. The sun is situated at one foci of the ellipse.
