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. Hydraulic Brakes work on which principle?
[A] Pascal’s Principle
[B] Archimedes Principle
[C] Newton’s Laws
[D] Casini’s Laws
Show Answer
Correct Answer: A [Pascal’s Principle]
Notes:
In 1647 the French scientist Blaise Pascal (1623–1662) discovered that water exerts the same pressure in all directions. This statement is known as Pascal’s Principle.
Pascal’s law states that increase in pressure at a point in the enclosed liquid in equilibrium is transmitted equally in all directions in liquid and to the Walls of the container. The working of hydraulic lift, hydraulic press and hydraulic brakes are based on Pascal’s law.
2. 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.
3. On which of the following Inertia of an object depends ?
[A] Bulk
[B] Size
[C] Shape
[D] Mass
Show Answer
Correct Answer: D [Mass]
Notes:
Inertia is the resistance experienced by an object to any change in its velocity. This includes changes to the object’s speed, or direction of motion. Inertia of rest, Inertia of motion are the examples.
4. Who among the following is known to manufacture first Cyclotron?
[A] Ernest Lawrence
[B] Niels Bohr
[C] Rutherford
[D] Max Born
Show Answer
Correct Answer: A [Ernest Lawrence]
Notes:
A cyclotron is a type of particle accelerator invented by Ernest O. Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. A cyclotron accelerates charged particles outwards from the center along a spiral path.
5. Two Flat mirrors are placed at an angle of 60° from each other. How many images will be formed of a Candle placed in between them?
[A] 3
[B] 4
[C] 5
[D] 6
Show Answer
Correct Answer: C [5]
Notes:
If two flat mirrors are placed at an angle ø. Then number of images of an object placed between mirrors are = (360/ø) – 1 .
Here ø = 60
So, number of images of candle = (360/60) -1
SO there will be 5 images.
6. What is the distance covered by a bus moving at a speed of 72 km/hr in a duration of 5 seconds?
[A] 50 meters
[B] 60 meters
[C] 74.5 meters
[D] 100 meters
Show Answer
Correct Answer: D [100 meters]
Notes:
The solution involves converting the speed of the bus from km/hr to m/sec. This conversion is achieved by the formula speed (m/sec) = speed (km/hr) * 5/18. Thus, the speed becomes 20 m/s. The distance travelled by the bus in 5 seconds is the product of speed and time which gives us 100 meters. Therefore, option [D] or option 4 is the correct answer.
7. How the brain interprets the frequency of an emitted sound is called its __:
[A] Pitch
[B] Amplitude
[C] Intensity
[D] Timbre
Show Answer
Correct Answer: A [ Pitch]
Notes:
How the brain interprets the frequency of an emitted sound is called the pitch. Researchers have discovered a discrete region of the monkey brain that processes pitch, the relative high and low points of sound, by recognizing a single musical note played by different instruments.
8. Which of the following is the unit of Solid Angle?
[A] radian
[B] steradian
[C] m2
[D] π
Show Answer
Correct Answer: B [ steradian ]
Notes:
Steradian is the unit of Solid Angle (Angle in Space). One steradian is defined as the solid angle of a sphere subtended at the centre of a sphere by that surface of the surface whose area is equal to the square of the sphere’s radius. Its symbol is sr.
9. What is represented by the slope of a straight line joining two points on a velocity-time graph?
[A] Average velocity
[B] Instantaneous acceleration
[C] Average acceleration
[D] None of the above
Show Answer
Correct Answer: C [Average acceleration]
Notes:
The slope of a straight line joining two points on a velocity-time graph gives the average acceleration between these two points. Depending on the sign of slope, the average acceleration can be positive or negative.
10. 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