Chapter Overview

Physics in everyday life (दैनिक जीवन में भौतिकी) is the general-science physics that a CGPSC aspirant needs. It is pitched at roughly Class 9–10 NCERT level and always asked through applications: why passengers lurch when a bus brakes, why the sky is blue, why a fuse melts, how a transformer works. Formulas are few and simple; the exam tests whether you can name the principle behind an everyday event.

What You’ll Learn

By the end of this chapter, you will be able to:

Explain everyday events with Newton’s laws, inertia, momentum and friction
Distinguish mass from weight, explain weightlessness, and quote escape velocity and the geostationary height
Apply Pascal’s, Archimedes’ and Bernoulli’s principles to brakes, ships and aeroplanes
Explain refraction, total internal reflection, dispersion and scattering with their classic examples (twinkling stars, diamonds, rainbows, blue sky)
Match eye defects to the correcting lens
Explain the speed, pitch and loudness of sound, the uses of ultrasound, the Doppler effect and India’s noise standards
Use Ohm’s law, explain household wiring, fuses and earthing, and calculate an electricity bill in kWh
Explain motors, generators and transformers, and link them to how Chhattisgarh’s power reaches homes

Prerequisites

No formal prerequisite: this chapter starts the Science & Technology section.
Comfort with Class 10 science vocabulary helps. Every formula on these pages is explained in words.

Learning Path

Follow the topics in this order:

graph TD
    A["1. Motion and Force
Newton's laws, friction,
gravitation, pressure, fluids"] --> B["2. Light and Sound
Optics, eye, scattering,
ultrasound, Doppler, noise"]
    B --> C["3. Electricity and Magnetism
Ohm's law, wiring, safety,
motor, generator, transformer"]
    C --> D["4. Quick Revision
One-page sheet"]
    D --> E["Next chapter:
Chemistry in Everyday Life"]

Topics in This Chapter

#	Topic	What it covers
1	Motion and Force	Distance, velocity, acceleration; Newton’s three laws; momentum and impulse (seat belts, airbags); friction; circular motion and banking; gravitation, g, mass vs weight, weightlessness, escape velocity; pressure, Pascal, Archimedes, Bernoulli
2	Light and Sound	Mirrors and their uses; refraction and twinkling; total internal reflection (diamond, optical fibre, mirage); dispersion and rainbow; scattering; Raman effect; lenses and eye defects; speed of sound, pitch and loudness, infrasound and ultrasound, echo, Doppler effect, sonic boom, decibels and the Noise Rules, 2000
3	Electricity and Magnetism	Current, voltage, resistance, Ohm’s law; series vs parallel; heating effect (nichrome, tungsten, fuse); kWh; domestic circuits, wire colours, fuse, MCB, earthing, RCCB; AC vs DC; magnets and Earth’s field; Oersted, electromagnets; motor; Faraday’s induction, generator, transformer
—	Quick Revision	Every law, value, unit and application on one page

Where It Is Asked

Paper	What to expect
Prelims P-I (Part 1, India GS)	Application MCQs: “which principle explains…”, device–principle matching, values (speed of light and sound, escape velocity, audible range), eye defects, wire and safety-device questions. Statement-based formats are common
Mains P-IV (GS-II), Science section	Short explanations (blue sky, weightlessness, fuse vs earthing, AC vs DC) and longer answers on applications: ultrasound in medicine, electricity generation and transmission, physics behind road safety

Exam focus

High-yield: Newton’s third law (rocket), inertia examples, g at poles vs equator, Pascal/Archimedes/Bernoulli, total internal reflection, scattering, eye defects and lenses, ultrasound uses, motor vs generator, transformers and AC.
Common mistakes: “no gravity in space”, “sound travels fastest in air”, “red is scattered most”, “transformers work with DC”, “fuse in parallel”.
Chhattisgarh angle for Mains: Korba as the state’s “power capital” (generation and transmission); ghat roads such as Keshkal (road-safety physics); the rainbow at Chitrakote (optics in a local setting).

Quick Reference: Key Values and Principles

Item	Value or principle
g on Earth	About 9.8 m/s²; maximum at poles, minimum at equator
Escape velocity (Earth)	About 11.2 km/s
Geostationary orbit	About 35,786 km above the equator
Speed of light (vacuum)	About \( 3 \times 10^{8} \) m/s
Speed of sound (air, 20 °C)	About 343 m/s; solids > liquids > gases
Audible range	20 Hz – 20 kHz
Near point of normal eye	About 25 cm
Household supply (India)	230 V nominal (NCERT: 220 V), 50 Hz AC
1 kWh (“unit”)	\( 3.6 \times 10^{6} \) J
Hydraulic brakes	Pascal’s law
Ships float	Archimedes’ principle
Aeroplane lift	Bernoulli’s principle
Optical fibre, diamond sparkle	Total internal reflection
Blue sky, red sunset	Scattering
Motor / generator	Fleming’s left-hand / right-hand rule
Generator, transformer	Electromagnetic induction (Faraday, 1831)

Start Learning

Begin with the first topic:

→ Motion and Force