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. Which among the following radiations in the Sunlight causes tanning and sunburn?
[A] Ultraviolet
[B] Visible
[C] Infrared
[D] Micro waves
Show Answer
Correct Answer: A [Ultraviolet]
Notes:
The sunlight that reaches the earth has ultraviolet A and ultraviolet B (UVA and UVB) rays. These ultraviolet rays are the main causes of damage to the skin from the sun. UVA and UVB rays affect the skin’s sensitivity to sun exposure in different ways.
3. If in a closed room , the door of a refrigerator is kept open for some time , the temperature of room will ?
[A] Increase
[B] Decrease
[C] Remains same
[D] First decrease then become stable
Show Answer
Correct Answer: A [Increase]
Notes:
A refrigerator is like a heat engine. It extracts heat from low temperature reservoir and transfer it to high temperature. If a refrigerator’s door is kept open, then room will become hot, because then refrigerator exhaust more heat into the room than earlier.
4. Which among the following has highest velocity ?
[A] Hurricane
[B] Tornado
[C] Typhoon
[D] Cyclone
Show Answer
Correct Answer: B [Tornado]
Notes:
Tornadoes has the highest velocity and are more devastating compared to other types of cyclones. They generally occur in the pacific ocean.
5. Which of the following is an instrument for measuring electric charge or electrical potential difference?
[A] Ammeter
[B] Voltmeter
[C] Electrometer
[D] ohmmeter
Show Answer
Correct Answer: B [Voltmeter]
Notes:
Voltmeter is an instrument for measuring electric charge or electrical potential difference. It was invented by Hans Christian Oersted.
6. Which among the following temperature scale is based upon absolute zero?
[A] Celsius
[B] Fahrenheit
[C] Kelvin
[D] Rankine
Show Answer
Correct Answer: C [Kelvin]
Notes:
Kelvin is the base unit of temperature (SI unit), having the unit symbol K. The Kelvin temperature scale has an absolute zero (0°K) below which temperatures do not exist. It is the lowest possible temperature. At this temperature there is no motion and no heat. It is equivalent to 0°K, or -273.15° C, or at -460° F.
7. Which among the following is the most acceptable range of LEO (Low Earth orbit)?
[A] 350 – 2,600 kms
[B] 200-2000 kms
[C] 160 – 2,000 kms
[D] 160-1600 kms
Show Answer
Correct Answer: C [160 – 2,000 kms]
Notes:
This range is commonly used and accepted in the context of satellite orbits within the Earth’s atmosphere. It extends from approximately 160 kilometers (the Kármán line, which is often used as the boundary of space) to around 2,000 kilometers above the Earth’s surface.
8. Which among the following waves are used in the gemstone industry to change white topaz into blue topaz?
[A] X-Rays
[B] Gamma Rays
[C] Alpha Radiation
[D] Beta Radiation
Show Answer
Correct Answer: B [Gamma Rays]
Notes:
Gamma rays is commonly used in gemstone industry to change white topaz into blue topaz. Because white topaz is heat-treated to turn into blue topaz, the value of blue topaz is often decreased.
9. If earth stops rotating, the impact on weight of a body will be minimum on which among the following places?
[A] Equator
[B] North Pole
[C] Tropic of Cancer
[D] Tropic of Capricorn
Show Answer
Correct Answer: B [North Pole]
Notes:
The question is related to the centrifugal forces, which represent the effects of inertia that arise in connection with rotation and which are experienced as an outward force away from the center of rotation. The impact of this force is maximum at Equator and minimum at Pole.
10. An Electric generator is based on which of the following scientific principles?
[A] Faraday’s law of Electromagnetic Induction
[B] Super Conductivity
[C] Laws of Thermodynamics
[D] Newton’s Law of Motion
Show Answer
Correct Answer: A [Faraday’s law of Electromagnetic Induction]
Notes:
An Electric generator works on the principle of Faraday’s law of Electromagnetic Induction. An electric generator uses mechanical energy to generate electricity applying Faraday’s law of induction. It spins a coil at a constant rate in a magnetic field to induce an oscillating emf.
