Physics Class 7 ICSE FAQs
1. What is the basic definition of physics? |
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Ans. Physics is the branch of science that deals with the study of matter, energy, and the interactions between them. It helps us understand how the universe behaves through concepts such as force, motion, energy, and waves.
2. What are the different branches of physics covered in Class 7? |
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Ans. In Class 7, the main branches of physics include mechanics (study of motion and forces), optics (study of light), thermodynamics (study of heat), and electromagnetism (study of electricity and magnetism).
3. How does the concept of force relate to motion? |
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Ans. A force is a push or pull that can cause an object to start moving, stop moving, or change its direction. The relationship between force and motion is described by Newton's laws of motion, which explain how forces affect the movement of objects.
4. What is the difference between speed and velocity? |
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Ans. Speed is a scalar quantity that refers to how fast an object is moving, calculated as distance traveled over time. Velocity, on the other hand, is a vector quantity that includes both speed and direction.
5. Can you explain what energy is and its different forms? |
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Ans. Energy is the capacity to do work. It exists in various forms, including kinetic energy (energy of motion), potential energy (stored energy due to position), thermal energy (heat), and chemical energy (stored in chemical bonds).
6. What is the law of conservation of energy? |
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Ans. The law of conservation of energy states that energy cannot be created or destroyed; it can only be transformed from one form to another. The total energy in a closed system remains constant.
7. What is friction, and how does it affect motion? |
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Ans. Friction is a force that opposes the relative motion of two surfaces in contact. It can slow down or stop moving objects and is essential for activities like walking, driving, and holding objects.
8. How do we measure force? |
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Ans. Force is measured in newtons (N) using a device called a force meter or spring scale. The amount of force is calculated by multiplying mass by acceleration (F = m × a).
9. What are simple machines, and why are they important? |
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Ans. Simple machines are devices that make work easier by allowing us to apply less force over a greater distance. Examples include levers, pulleys, inclined planes, and wedges. They help reduce the effort needed to perform tasks.
10. How does gravity affect objects on Earth? |
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Ans. Gravity is a force that attracts objects toward each other. On Earth, it gives weight to objects and causes them to fall when dropped. The strength of gravity depends on the mass of the objects and the distance between them.
11. What is the difference between conductors and insulators? |
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Ans. Conductors are materials that allow electric current to flow easily, such as metals like copper and aluminum. Insulators, on the other hand, resist the flow of electric current, examples being rubber, glass, and wood.
12. How does light travel, and what is reflection? |
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Ans. Light travels in straight lines and can be reflected off surfaces. Reflection occurs when light bounces off an object, allowing us to see images. The angle of incidence equals the angle of reflection.
13. What are sound waves, and how do they travel? |
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Ans. Sound waves are vibrations that travel through a medium (solid, liquid, or gas) as longitudinal waves. They require a medium to propagate, and their speed varies depending on the medium's density and elasticity.
14. Why is it essential to study physics in daily life? |
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Ans. Studying physics is essential as it helps us understand the fundamental principles that govern the natural world. Knowledge of physics enables us to solve practical problems, innovate technology, and make informed decisions in everyday life.
15. What role do scientific experiments play in physics? |
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Ans. Scientific experiments are crucial in physics as they allow us to test hypotheses, observe phenomena, and gather data. Through experimentation, we can confirm theories, discover new principles, and enhance our understanding of the physical universe.