The Physical World Class 11 Physics MCQs series contains 370 multiple-choice questions spread across 4 parts. Each of the first three parts carries 100 questions, while Part 4 includes 70. Every part restarts numbering from 1, making the set easy to follow. These practice questions are fully aligned with the NCERT/CBSE syllabus and serve as a valuable resource for board preparation, entrance exams (NEET, JEE), and concept strengthening.
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Correct Answer: Invention of lasers and fiber optics for transmitting data
Explanation: Physics contributed to modern telecommunications through the invention of lasers and fiber optics, enabling efficient transmission of data over long distances with minimal loss, revolutionizing communication technologies.
Correct Answer: Application of principles like X-rays, MRI, and ultrasound for visualizing internal body structures
Explanation: Physics plays a crucial role in medical imaging by applying principles such as X-rays, MRI (magnetic resonance imaging), and ultrasound to visualize internal body structures non-invasively, aiding in diagnosis and treatment planning.
Correct Answer: Application of principles like atomic clocks and satellite communication
Explanation: The development of GPS navigation systems benefited from physics through the application of principles like atomic clocks for precise timing and satellite communication for accurate positioning, enabling global navigation and location-based services.
Correct Answer: Application of principles like solar cells, wind turbines, and hydroelectric generators for sustainable energy production
Explanation: Physics has significantly impacted renewable energy technologies by applying principles such as solar cells, wind turbines, and hydroelectric generators to harness sustainable sources of energy, reducing dependence on fossil fuels.
Correct Answer: Application of principles to manipulate materials at the atomic and molecular scale for designing new materials and devices
Explanation: Physics plays a critical role in nanotechnology by applying principles to manipulate materials at the atomic and molecular scale, enabling the development of new materials with enhanced properties and applications in electronics, medicine, and more.
Correct Answer: Application of principles like quantum superposition and entanglement for performing computations
Explanation: Physics has contributed to quantum computing by applying principles like quantum superposition and entanglement to perform computations faster and solve complex problems that are intractable for classical computers.
Correct Answer: Application of principles to generate coherent light, used in industries, communications, and medical treatments
Explanation: Physics principles are applied in laser technology to generate coherent light through stimulated emission, used in various applications such as industrial cutting, telecommunications, medical treatments, and research.
Correct Answer: Application of principles like nuclear magnetic resonance (NMR) for medical imaging
Explanation: The development of MRI was enabled by applying principles like nuclear magnetic resonance (NMR) from physics, which allows non-invasive imaging of soft tissues and organs, providing detailed diagnostic information in medicine.
Correct Answer: Application of principles to develop integrated circuits, transistors, and semiconductor devices
Explanation: Physics has played a key role in semiconductor technology by applying principles to develop integrated circuits, transistors, and semiconductor devices essential for modern electronics, computing, and telecommunications.
Correct Answer: Application of principles like rocket propulsion, satellite communication, and space instrumentation
Explanation: Physics has made significant contributions to space exploration technology by applying principles like rocket propulsion, satellite communication systems, and advanced space instrumentation, enabling missions to explore distant planets, study cosmic phenomena, and enhance global communication networks.
Correct Answer: Application of principles like thermodynamics and heat transfer for cooling and preserving food
Explanation: Physics principles such as thermodynamics and heat transfer are applied in household appliances like refrigerators and air conditioners to cool and preserve food, maintain comfortable temperatures, and improve energy efficiency.
Correct Answer: Application of principles like mechanics, aerodynamics, and propulsion systems for efficient movement and travel
Explanation: Physics plays a crucial role in transportation systems by applying principles like mechanics for vehicle motion, aerodynamics for efficient airflow over vehicles, and propulsion systems for generating thrust, enhancing speed, safety, and fuel efficiency.
Correct Answer: Application of principles like electromagnetism, semiconductor physics, and quantum mechanics for device operation
Explanation: Physics contributes to electronic devices like smartphones and computers through principles like electromagnetism for signal transmission, semiconductor physics for integrated circuits, and quantum mechanics for device operation, enabling communication, computation, and information storage.
Correct Answer: Application of principles like mechanics, materials science, and aerodynamics for equipment design and athlete performance
Explanation: Physics impacts sports equipment and performance by applying principles like mechanics for motion analysis, materials science for equipment durability and performance, and aerodynamics for optimizing sports gear design, enhancing athlete performance and safety.
Correct Answer: Application of principles like solar panels, wind turbines, and energy storage systems for sustainable energy production
Explanation: Physics plays a crucial role in renewable energy technologies for household use by applying principles like solar panels for converting sunlight into electricity, wind turbines for harnessing wind energy, and energy storage systems for efficient energy management, promoting sustainable living.
Correct Answer: Application of principles like structural mechanics, materials science, and environmental physics for building stability, energy efficiency, and comfort
Explanation: Physics principles such as structural mechanics for building stability, materials science for construction materials, and environmental physics for energy-efficient design are applied in modern buildings, ensuring structural integrity, energy efficiency, and occupant comfort.
Correct Answer: Application of principles like electromagnetic waves, acoustics, and optics for medical imaging and diagnosis
Explanation: Physics contributes to medical technologies like MRI and ultrasound through principles like electromagnetic waves for MRI imaging, acoustics for ultrasound imaging, and optics for endoscopic procedures, enabling non-invasive diagnostics and medical treatments.
Correct Answer: Application of principles like sensors, remote sensing, and environmental physics for monitoring air and water quality, climate change, and natural disasters
Explanation: Physics plays a vital role in environmental monitoring technologies by applying principles like sensors for detecting pollutants, remote sensing for monitoring large-scale environmental changes, and environmental physics for understanding climate dynamics and mitigating natural disasters.
Correct Answer: Application of principles like heat transfer, refrigeration, and packaging materials for food safety, preservation, and shelf-life extension
Explanation: Physics principles such as heat transfer for cooking and pasteurization, refrigeration for cold storage, and packaging materials for food safety are applied in food processing and preservation technologies, ensuring food quality, safety, and shelf-life extension.
Correct Answer: Application of principles like optics, acoustics, and electronics for immersive audiovisual experiences and virtual environments
Explanation: Physics influences entertainment technologies like audiovisual systems and virtual reality by applying principles like optics for display technologies, acoustics for sound reproduction, and electronics for creating immersive virtual environments, enhancing entertainment experiences.
Correct Answer: Application of principles like nuclear magnetic resonance (NMR) and electromagnetic waves for non-invasive imaging
Explanation: Physics contributes to MRI technology through principles like nuclear magnetic resonance (NMR) for detecting atomic nuclei in magnetic fields and electromagnetic waves for generating detailed images of internal body structures, aiding in medical diagnosis and research.
Correct Answer: Application of principles like ionizing radiation and electromagnetic waves for imaging bones and soft tissues
Explanation: Physics plays a crucial role in X-ray imaging technology by applying principles like ionizing radiation to penetrate tissues and electromagnetic waves to create detailed images of bones and soft tissues, enabling medical diagnosis and treatment planning.
Correct Answer: Application of principles like sound waves and Doppler effect for imaging organs and blood flow
Explanation: Physics contributes to ultrasound imaging by applying principles like sound waves for imaging internal organs and tissues, and the Doppler effect for visualizing blood flow and detecting abnormalities non-invasively, enhancing medical diagnostics.
Correct Answer: Application of principles like ionizing radiation and particle accelerators for targeting and destroying cancer cells
Explanation: Physics impacts radiation therapy by applying principles like ionizing radiation to target and destroy cancer cells, and particle accelerators for generating high-energy beams that precisely deliver radiation, improving cancer treatment outcomes and patient care.
Correct Answer: Application of principles like stimulated emission of photons and optics for surgical procedures and therapeutic treatments
Explanation: Physics plays a significant role in laser technology for medical applications by applying principles like stimulated emission of photons to produce coherent light and optics for precise surgical procedures, therapeutic treatments, and non-invasive interventions, advancing medical care.
Correct Answer: Application of principles like X-rays, detectors, and computer algorithms for detailed cross-sectional imaging
Explanation: Physics contributes to CT scan technology by applying principles like X-rays for penetrating tissues, detectors for capturing attenuation data, and computer algorithms for reconstructing detailed cross-sectional images, facilitating accurate medical diagnosis and treatment planning.
Correct Answer: Application of principles like radioactive tracers, gamma rays, and detectors for functional imaging of organs and tissues
Explanation: Physics plays a critical role in PET imaging by applying principles like radioactive tracers emitting positrons, gamma rays for detecting annihilation events, and detectors for capturing signals, enabling functional imaging of organs and tissues for medical diagnostics and research.
Correct Answer: Application of principles like electronics, electromagnetism, and biophysics for cardiac rhythm management
Explanation: Physics principles are applied in medical devices like pacemakers and defibrillators through electronics for controlling cardiac rhythms, electromagnetism for generating therapeutic impulses, and biophysics for understanding physiological responses, enhancing cardiac health management and patient care.
Correct Answer: Application of principles like biomechanics, materials science, and robotics for designing functional prosthetics and rehabilitation devices
Explanation: Physics contributes to prosthetics and rehabilitation technologies by applying principles like biomechanics for analyzing human movement, materials science for developing durable prosthetic components, and robotics for enhancing mobility and function, improving quality of life for individuals with disabilities.
Correct Answer: Application of principles like electrical potentials, signal processing, and neurophysics for studying brain activity
Explanation: Physics plays a crucial role in EEG technology by applying principles like electrical potentials to measure brain activity, signal processing for analyzing neural signals, and neurophysics for understanding brain function, enabling non-invasive monitoring and diagnosis of neurological disorders.
Correct Answer: Application of principles like orbital mechanics, electromagnetic waves, and signal processing for transmitting and receiving signals
Explanation: Physics contributes to communication satellites through principles like orbital mechanics for satellite positioning, electromagnetic waves for signal transmission, and signal processing for efficient data handling, enabling global communication networks and satellite-based services.
Correct Answer: Application of principles like total internal reflection, optics, and data transmission for transmitting light signals through optical fibers
Explanation: Physics plays a critical role in fiber optics technology by applying principles like total internal reflection for guiding light within optical fibers, optics for controlling light properties, and data transmission techniques for high-speed internet and telecommunications, enhancing data transfer efficiency and bandwidth capacity.
Correct Answer: Application of principles like radio frequency propagation, antenna design, and spectrum management for efficient wireless communication
Explanation: Physics principles such as radio frequency propagation for signal transmission, antenna design for signal reception, and spectrum management for allocating frequencies impact wireless communication technologies like cellular networks, ensuring reliable and efficient mobile communication services.
Correct Answer: Application of principles like radio waves, signal processing, and Doppler effect for detecting and tracking objects
Explanation: Physics contributes to radar technology by applying principles like radio waves for object detection, signal processing for data analysis, and Doppler effect for velocity measurement, enabling applications in weather monitoring, air traffic control, and military surveillance, enhancing safety and operational efficiency.
Correct Answer: Application of principles like satellite orbits, time synchronization, and signal triangulation for precise location tracking
Explanation: Physics plays a crucial role in GPS technology through principles like satellite orbits for positioning satellites, time synchronization for accurate signal transmission, and signal triangulation for determining precise location coordinates, facilitating global navigation, mapping, and location-based services.
Correct Answer: Application of principles like geostationary orbits, microwave transmission, and signal modulation for transmitting TV signals via satellites
Explanation: Physics contributes to satellite communication for TV broadcasting through principles like geostationary orbits for satellite stability, microwave transmission for signal propagation, and signal modulation techniques for encoding TV signals, enabling global television broadcasting and satellite TV services.
Correct Answer: Application of principles like laser optics, data encoding, and fiber optics for high-speed data transmission
Explanation: Physics principles are applied in optical communication technologies like lasers through principles like laser optics for generating coherent light, data encoding for information transmission, and fiber optics for guiding light signals, enabling high-speed data communication in telecommunications, internet services, and data networks.
Correct Answer: Application of principles like sound propagation, signal processing, and underwater acoustics for transmitting messages through water
Explanation: Physics contributes to underwater communication systems through principles like sound propagation for transmitting acoustic waves, signal processing for data interpretation, and underwater acoustics for optimizing communication efficiency, facilitating underwater exploration, navigation, and military operations.
Correct Answer: Application of principles like quantum entanglement, superposition, and quantum states for secure data transmission and information processing
Explanation: Physics plays a significant role in quantum communication technologies through principles like quantum entanglement for secure key distribution, superposition for encoding quantum states, and quantum states for transmitting information, enabling highly secure communication channels and advanced quantum computing applications.
Correct Answer: Application of principles like data encoding, signal modulation, and network protocols for reliable data transmission and network interoperability
Explanation: Physics principles are applied in communication protocols and standards through principles like data encoding for information representation, signal modulation for signal transmission, and network protocols for defining communication rules, ensuring reliable data exchange and network interoperability in internet and telecommunications systems.
Correct Answer: Understanding the physical processes affecting the environment and natural resources
Explanation: Environmental physics focuses on understanding the physical processes that impact the environment and natural resources, including climate change, renewable energy, atmospheric dynamics, and environmental pollution.
Correct Answer: Biophysics
Explanation: Biophysics within environmental physics focuses on studying the interactions between living organisms and their environment, including ecosystems, biodiversity, and environmental adaptations.
Correct Answer: Application of principles like radiative transfer, thermodynamics, and atmospheric dynamics to study the impact of greenhouse gases on Earth’s climate
Explanation: Physics principles such as radiative transfer for energy absorption, thermodynamics for heat exchange, and atmospheric dynamics for air circulation are applied to understand how greenhouse gases trap heat in the atmosphere, leading to climate change.
Correct Answer: Application of principles like solar radiation, wind dynamics, and energy conversion technologies for harnessing renewable energy
Explanation: Environmental physics plays a crucial role in developing renewable energy sources such as solar and wind energy by applying principles like solar radiation for photovoltaic cells, wind dynamics for wind turbines, and energy conversion technologies for generating clean electricity.
Correct Answer: Application of principles like atmospheric chemistry, pollutant dispersion, and health risk assessment to analyze air quality and its health effects
Explanation: Environmental physics contributes to studying air pollution by applying principles like atmospheric chemistry to identify pollutants, pollutant dispersion models to track their movement, and health risk assessment to understand their impact on public health.
Correct Answer: Application of principles like electromagnetic radiation, satellite imaging, and data analysis for monitoring environmental changes from space
Explanation: Physics principles such as electromagnetic radiation for remote sensing, satellite imaging for capturing Earth’s surface, and data analysis techniques for interpreting environmental changes are applied in environmental monitoring technologies, enabling assessment of ecosystems, climate patterns, and land use changes.
Correct Answer: Application of principles like ocean currents, thermohaline circulation, and carbon cycle dynamics for understanding oceanic processes and their influence on global climate
Explanation: Environmental physics applies principles like ocean currents for water movement, thermohaline circulation for deep ocean currents, and carbon cycle dynamics for carbon dioxide absorption to study ocean dynamics and their role in regulating global climate patterns.
Correct Answer: Application of principles like ecosystem modeling, biodiversity assessment, and land surface interactions for analyzing environmental changes due to deforestation
Explanation: Physics principles such as ecosystem modeling for predicting ecological changes, biodiversity assessment for species diversity, and land surface interactions for understanding soil and vegetation dynamics are applied to assess the environmental impact of deforestation and land use changes.
Correct Answer: Application of principles like soil water dynamics, nutrient cycling, and crop growth modeling for optimizing agricultural productivity and sustainability
Explanation: Environmental physics contributes to sustainable agriculture by applying principles like soil water dynamics for irrigation management, nutrient cycling for soil fertility, and crop growth modeling for optimizing yield and reducing environmental impact, promoting sustainable farming practices.
Correct Answer: Application of principles like climate modeling, energy efficiency, and pollution control technologies for designing environmental policies and regulations
Explanation: Physics principles such as climate modeling for predicting climate patterns, energy efficiency for reducing resource consumption, and pollution control technologies for minimizing emissions are applied in developing environmental policies and regulations to mitigate climate change and environmental degradation.
Correct Answer: Strong nuclear force
Explanation: The strong nuclear force is responsible for binding protons and neutrons together in atomic nuclei. It is a short-range force that overcomes the electrostatic repulsion between positively charged protons.
Correct Answer: Electromagnetic force
Explanation: The electromagnetic force is responsible for the attraction or repulsion between electrically charged particles. It includes both electric and magnetic forces and operates over long distances.
Correct Answer: Weak nuclear force
Explanation: The weak nuclear force is responsible for radioactive decay processes such as beta decay, where a neutron decays into a proton, an electron (beta particle), and an antineutrino.
Correct Answer: Gravitational force
Explanation: Gravitational force is responsible for the attraction between masses, governing the motion of planets around the Sun, the Moon around Earth, and objects falling towards the Earth’s surface.
Correct Answer: Gravitational force
Explanation: Gravitational force is the weakest of the fundamental forces but operates over infinite distances. It affects all objects with mass, causing attraction between them.
Correct Answer: Electromagnetic force
Explanation: The electromagnetic force mediates interactions between particles with electric charge, such as electrons and protons. It is responsible for electric and magnetic phenomena.
Correct Answer: Strong nuclear force
Explanation: The strong nuclear force binds quarks together to form protons, neutrons, and other hadrons. It is the strongest of the fundamental forces but operates over very short distances.
Correct Answer: Strong nuclear force
Explanation: Fusion reactions in stars, including the Sun, are driven by the strong nuclear force, which binds atomic nuclei together to release enormous amounts of energy.
Correct Answer: Weak nuclear force
Explanation: The weak nuclear force is responsible for the decay of subatomic particles such as muons and pions, contributing to processes in particle physics and astrophysics.
Correct Answer: Gravitational force
Explanation: Some theories in physics, such as Grand Unified Theories (GUTs), hypothesize that the gravitational force could unify with the weak nuclear force at very high energies, possibly explaining the fundamental forces as aspects of a single force.
Correct Answer: Newton’s Law of Gravitation
Explanation: Newton’s Law of Gravitation states that every mass attracts every other mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
Correct Answer: Newton (N)
Explanation: The SI unit of gravitational force is the Newton (N), named after Sir Isaac Newton, who formulated the law of gravitation.
Correct Answer: It decreases by a factor of 4
Explanation: According to Newton’s Law of Gravitation, gravitational force is inversely proportional to the square of the distance between two masses. Doubling the distance decreases the force by a factor of 4.
Correct Answer: It is quadrupled
Explanation: Gravitational force is directly proportional to the product of the masses and inversely proportional to the square of the distance between them. Doubling the masses and halving the distance results in a quadrupling of the gravitational force.
Correct Answer: 98 N
Explanation: Gravitational force, F = mass × acceleration due to gravity = 10 kg × 9.8 m/s² = 98 N.
Correct Answer: It doubles
Explanation: Gravitational force is directly proportional to the product of the masses. Doubling the mass of one object doubles the gravitational force.
Correct Answer: It decreases by a factor of 9
Explanation: Gravitational force is inversely proportional to the square of the distance between two objects. Tripling the distance decreases the force by a factor of 9.
Correct Answer: At the center of the Earth
Explanation: Gravitational acceleration due to Earth’s gravity becomes zero at the center of the Earth because the mass around cancels out the gravitational forces acting on a body at that point.
Correct Answer: Directly proportional
Explanation: Gravitational force between two objects is directly proportional to the product of their masses according to Newton’s Law of Gravitation.
Correct Answer: Density of the objects
Explanation: Gravitational force between two objects depends on their masses and the distance between them, not their densities.
Correct Answer: It decreases by a factor of 16
Explanation: Gravitational force is inversely proportional to the square of the distance between two masses. Increasing the distance by a factor of 4 decreases the force by a factor of 16.
Correct Answer: F = G × m₁ × m₂ / r²
Explanation: Newton’s Law of Gravitation is expressed as F = G × (m₁ × m₂) / r², where F is the gravitational force, G is the gravitational constant, m₁ and m₂ are the masses, and r is the distance between their centers.
Correct Answer: It doubles
Explanation: Gravitational force is directly proportional to the product of the masses. Doubling both masses doubles the gravitational force.
Correct Answer: 9 N
Explanation: Gravitational force is inversely proportional to the square of the distance between two masses. Doubling the distance reduces the force to one-fourth its original value (36 N / 4 = 9 N).
Correct Answer: The proportionality constant in the gravitational force equation
Explanation: The gravitational constant (G) is a fundamental constant in physics that appears in Newton’s Law of Gravitation, relating the gravitational force between two masses to their distance.
Correct Answer: 6.674 × 10⁻¹¹ N·m²/kg²
Explanation: The gravitational constant (G) is approximately 6.674 × 10⁻¹¹ N·m²/kg², and it plays a crucial role in determining the strength of gravitational interactions.
Correct Answer: It is always attractive and acts along the line joining the centers of masses
Explanation: Gravitational force is always attractive, pulling objects toward each other along the line joining their centers of mass, as described by Newton’s Law of Gravitation.
Correct Answer: It quadruples
Explanation: Gravitational force is inversely proportional to the square of the distance between two masses. Halving the distance increases the force by a factor of 4.
Correct Answer: N·m²/kg²
Explanation: The gravitational constant (G) has the unit of N·m²/kg² in the SI system, reflecting its role in determining the magnitude of gravitational force between masses.
Correct Answer: It decreases by a factor of 9
Explanation: Gravitational force is inversely proportional to the square of the distance between two masses. Tripling the distance decreases the force by a factor of 9.
Correct Answer: Electric force and magnetic force
Explanation: The electromagnetic force involves electric and magnetic forces, which are unified as electromagnetic interactions.
Correct Answer: James Clerk Maxwell
Explanation: James Clerk Maxwell formulated the equations that describe electromagnetism, unifying electric and magnetic phenomena.
Correct Answer: It is the strongest force
Explanation: The electromagnetic force is stronger than the gravitational force and the weak nuclear force but comparable to the strong nuclear force.
Correct Answer: Repel, attract
Explanation: Like charges repel each other, and opposite charges attract each other due to the electromagnetic force.
Correct Answer: Electromagnetic force
Explanation: The electromagnetic force between the positively charged nucleus and negatively charged electrons holds electrons in orbit around the nucleus.
Correct Answer: Electromagnetic induction
Explanation: Electromagnetic induction is the process where a magnetic field is created around a conductor carrying an electric current.
Correct Answer: Maxwell’s Equations
Explanation: Maxwell’s Equations describe how electric charges and currents create electric and magnetic fields.
Correct Answer: Tesla (T)
Explanation: The SI unit of magnetic field intensity (or magnetic flux density) is the Tesla (T).
Correct Answer: Ampere force
Explanation: The force between two parallel current-carrying conductors is known as the Ampere force.
Correct Answer: Electromagnetic induction
Explanation: Electromagnetic induction is the phenomenon that allows the operation of transformers and electric motors by generating electric currents or voltages due to changing magnetic fields.
Correct Answer: The force is reduced to one-ninth
Explanation: Coulomb’s Law states that the electrostatic force between two charges is inversely proportional to the square of the distance between them. Therefore, if the distance is tripled, the force decreases by a factor of \( 3^2 = 9 \).
Correct Answer: Repulsive
Explanation: Like charges repel each other according to Coulomb’s Law, so the electrostatic force between two positively charged particles is repulsive.
Correct Answer: The force is directly proportional to the product of charges
Explanation: Coulomb’s Law states that the electrostatic force \( F \) between two charges is directly proportional to the product of their charges \( q_{1} \) and \( q_{2} \), i.e., \( F \propto q_{1} \cdot q_{2} \).
Correct Answer: Coulomb (C)
Explanation: Coulomb is the SI unit of electric charge, denoted by the symbol C.
Correct Answer: \( F = k \cdot \frac{q_{1} \cdot q_{2}}{r^{2}} \)
Explanation: Coulomb’s Law states that the magnitude of the electrostatic force \( F \) between two point charges is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance \( r \) between them.
Correct Answer: Coulomb’s constant
Explanation: Coulomb’s constant ( k ) appears in Coulomb’s Law and determines the strength of the electric force between charges.
Correct Answer: 2 N
Explanation: Doubling the distance between two charges reduces the force between them to one-fourth of its original value, so if the force is initially 4 N, it would become 1 N when the distance is doubled.
Correct Answer: Superposition principle
Explanation: Coulomb’s Law follows the superposition principle, which states that the net force exerted by several charges on a charge is the vector sum of the individual forces exerted by each charge separately.
Correct Answer: Stationary
Explanation: Coulomb’s Law describes the force between stationary electric charges, assuming they are not moving relative to each other.
Correct Answer: Attractive
Explanation: Charges of opposite signs attract each other according to Coulomb’s Law.