MCQs On Physical World

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Physical world includes the complexity of the natural world around us. It is a kind of analysis of the physical world around us to understand how it works. The fundamental forces that govern nature are:

Gravitational Force is a universal force that exists as a result of mutual attraction between any two objects with respect to their masses.
Electromagnetic Force can be understood as the force that exists between the charged particles. The force is given by Coulomb’s law.
Strong Nuclear Force is the force that binds the protons and neutrons in a nucleus. Of all the fundamental forces in nature, a strong nuclear force is the strongest as its name suggests.
Weak Nuclear Force can only be observed in some of the nuclear processes. For instance, the beta decay of the nucleus.

The conservation laws in physics are very important to understand the working of nature around us. These laws include Laws of Conservation of Mass, Laws of Conservation of Momentum, Laws of Conservation of Energy, and Laws of Conservation of Charge.

Ques 1. Who discovered the law of inertia?

Archimedes
Isaac Newton
Galileo Galilei
Albert Einstein

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Ans: c. Galileo Galilei

Explanation: The law of inertia states that a body will remain in the same state of motion till no net force is applied over it. Galileo’s law of inertia is also known as Newton’s first law of motion. It can also be understood as a body that is moving at a constant speed in a straight line or is at rest will continue to move in the straight line or remain at rest until and unless it is acted on by an external force.

Ques 2. LASER acronym is used for

Light amplification by stimulated emission of radiation
Light attenuation by stimulated emission of radiation
Both a and b
None of the above

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Ans: a. Light amplification by stimulated emission of radiation

Explanation: LASER is a device that emits light. The electrons move from lower to higher energy orbit. The electron gets excited when atoms in optometric materials such as crystal, gas or glass absorb the energy from light or electrical current.

Ques 3. In which of the following, Newton’s law of motion is used as the scientific principle?

Electric Generators
Rocket Propulsion
Computers
All of the above

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Ans: b. Rocket Propulsion

Explanation: Newton’s third law of motion is the scientific principle used in Rocket Propulsion. Thrust through action and reaction is produced by a rocket engine. The hot gases produced by the engine of rocket flow out through the back of the engine. As a result of this action, thrusting force is produced in the opposite reaction.

Ques 4. Which of the following is the strongest force among the other fundamental forces?

Electromagnetic Force
Weak Nuclear Force
Strong Nuclear Force
Gravitational Force

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Ans: c. Strong Nuclear Force

Explanation: On exchanging of the particles a strong nuclear force is created between Nucleons. The force which exists between Neutrons and protons to keep the nucleus together is the Strong Nuclear Force. It is the strongest force among the four fundamentals forces present in nature.

Ques 5. Which force is charge independent?

Gravitational Force
Weak Nuclear Force
Strong Nuclear Force
Electromagnetic Force

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Ans: c. Strong Nuclear Force

Explanation: The Strong Nuclear Force is charge independent. When the electromagnetic forces are ignored, the force between two neutrons, two protons or a neutron and a proton in the quantum mechanical state is nearly the same.

Ques 6. What is the range of the electromagnetic force?

Infinite
Finite
Short
Very short

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Ans: a Infinite

Explanation: The Electromagnetic force is the same of the same form as the gravitational force. It obeys the inverse square law and the force is of an infinite range. The electromagnetic force acts on the particles that are electrically charged.

Ques 7. The principle of reflection of the ultrasonic waves is used in

Optical Fiber
LASER
RADAR
SONAR

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Ans: d. SONAR

Explanation: The SONAR is a technique that uses sound propagation to measure distances, navigation, communication or detection of objects that are present on or under the water surface. It uses reflected and transmitted underwater sound waves for the detection of objects that are submerged under the water. SONAR helps to locate the object by measuring the distance.

Ques 8. Which principle is used in the optical fibres?

Total internal refraction
Total internal reflection
Both a and b
None of the above

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Ans: b. Total Internal Reflection

Explanation: Optical fibres work on the principle of Total Internal Reflection. Optical Fibre is a thin rod made up of high-quality glass, The light enters from one end of the optical fibre and is repeatedly reflected internally and emerges at the other end. This principle of total internal reflection is used in the working of Cameras, telescopes, periscopes and binoculars.

Ques 9. The photoelectric effect is the principle that is used in

SONAR
LASER
Computers
photocell

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Ans: d. Photocell

Explanation: The device that uses the photoelectric effect is known as Photocells. A metal emits electrons when light strikes the metal and the other metal plate present in the photocell. Photocells are used for the light-sensitive applications of automatic on-at-dusk street lights and photographic light meters. Photocells are also used for counting the vehicles on the roads.

Ques 10. Who discovered X-rays?

W K Roentgen
J J Thomson
J C Bose
Albert Einstein

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Ans: a. W K Roentgen

Explanation: An X ray is a test that helps in producing images of bone structure from inside the body. The beams are passed through the body. Depending on the material through which the rays are passed, they are absorbed in different amounts. It helps doctors in checking the symptoms of the body, diagnosing injuries, joint changes and arthritis.

Read Also:

Gravity Waves	Effects of Force	Specific Gravity
Difference Between Gravitation and Gravity	Motion	Mass and Momentum
Reduction Potential	Force of Friction	Electrolytic Cell
Semiconductor Diode	Dielectric Properties	VI Characteristics

MCQs On Physical World

CBSE CLASS XII Related Questions

2.
The energy of an electron in an orbit in hydrogen atom is \( -3.4 \, \text{eV} \). Its angular momentum in the orbit will be:

3.
A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

4.
Assertion : In Young’s double-slit experiment, the fringe width for dark and bright fringes is the same. Reason (R): Fringe width is given by \( \beta = \frac{\lambda D}{d} \), where symbols have their usual meanings.

5.
Assertion : Photoelectric effect is a spontaneous phenomenon. Reason (R): According to the wave picture of radiation, an electron would take hours/days to absorb sufficient energy to overcome the work function and come out from a metal surface.

6.
The figure represents the variation of the electric potential \( V \) at a point in a region of space as a function of its position along the x-axis. A charged particle will experience the maximum force at:

Similar Physics Concepts

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MCQs On Physical World

CBSE CLASS XII Related Questions

2.The energy of an electron in an orbit in hydrogen atom is \( -3.4 \, \text{eV} \). Its angular momentum in the orbit will be:

3.A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

4.Assertion : In Young’s double-slit experiment, the fringe width for dark and bright fringes is the same. Reason (R): Fringe width is given by \( \beta = \frac{\lambda D}{d} \), where symbols have their usual meanings.

5.Assertion : Photoelectric effect is a spontaneous phenomenon. Reason (R): According to the wave picture of radiation, an electron would take hours/days to absorb sufficient energy to overcome the work function and come out from a metal surface.

6.The figure represents the variation of the electric potential \( V \) at a point in a region of space as a function of its position along the x-axis. A charged particle will experience the maximum force at:

Similar Physics Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

2.
The energy of an electron in an orbit in hydrogen atom is \( -3.4 \, \text{eV} \). Its angular momentum in the orbit will be:

3.
A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

4.
Assertion : In Young’s double-slit experiment, the fringe width for dark and bright fringes is the same. Reason (R): Fringe width is given by \( \beta = \frac{\lambda D}{d} \), where symbols have their usual meanings.

5.
Assertion : Photoelectric effect is a spontaneous phenomenon. Reason (R): According to the wave picture of radiation, an electron would take hours/days to absorb sufficient energy to overcome the work function and come out from a metal surface.

6.
The figure represents the variation of the electric potential \( V \) at a point in a region of space as a function of its position along the x-axis. A charged particle will experience the maximum force at: