Physics : Detailed Notes with Top MCQ

1. Motion,
2. Force,
3. Work & Energy,
4. Heat,
5. Light,
6. Sound,
7. Electricity and Magnetism

Chemistry:

1. Matter,
2. Atom,
3. Elements,
4. Compounds,
5. Acids-Bases-Salts,
6. Metals & Non-metals,
7. Chemical Reactions

Biology:

1. Cell,
2. Human Body Systems,
3. Nutrition,
4. Diseases,
5. Plant Biology,
6. Reproduction and Genetics

Environment:

1. Ecosystem,
2. Food Chain,
3. Biodiversity,
4. Pollution,
5. Climate Change,
6. Natural Resources and Conservation

Health Science:

1. Balanced Diet,
2. Vitamins,
3. Deficiency Diseases,
4. Communicable Diseases,
5. First Aid and Personal Hygiene

General Science – Short Notes for Karnataka KREIS Exam 2026

For the Karnataka KREIS Exam 2026, General Science generally requires a clear understanding of basic concepts from Physics, Chemistry, Biology, Environment and Health Science. The following notes are useful for quick revision.

1. Physics

Matter and Measurement

• Matter is anything that has mass and occupies space.

• SI unit of length – metre (m)

• SI unit of mass – kilogram (kg)

• SI unit of time – second (s)

• Density = Mass / Volume

Motion and Force

• Speed = Distance / Time

• Velocity is speed in a particular direction.

• Force can change the motion or shape of an object.

• SI unit of force – Newton (N)

• Newton’s laws explain the relationship between force and motion.

• Gravity is the force that attracts objects towards the Earth.

Work, Energy and Power

• Work = Force × Displacement

• SI unit of work – Joule (J)

• Energy is the capacity to do work.

• Main forms of energy: heat, light, sound, electrical, chemical and mechanical energy.

• SI unit of power – Watt (W).

Heat and Temperature

• Heat is a form of energy transferred from a hotter body to a colder body.

• Temperature indicates the degree of hotness or coldness.

• Common temperature scales: Celsius, Fahrenheit and Kelvin.

• Heat transfer occurs through conduction, convection and radiation.

Light

• Light generally travels in a straight line.

• Reflection is the bouncing back of light.

• Refraction is the bending of light when it passes from one medium to another.

• A convex lens can converge light.

• A concave lens diverges light.

Sound

• Sound is produced by vibrating objects.

• Sound needs a medium to travel.

• Sound cannot travel through a vacuum.

• Frequency determines the pitch of sound.

• Amplitude is related to the loudness of sound.

Electricity and Magnetism

• Electric current is the flow of electric charge.

• SI unit of current – Ampere (A)

• SI unit of resistance – Ohm (Ω)

• A magnet has two poles: North and South.

• Like magnetic poles repel; unlike poles attract.

2. Chemistry

Matter

Matter exists mainly as:

• Solid – fixed shape and volume

• Liquid – fixed volume but no fixed shape

• Gas – neither fixed shape nor fixed volume

Elements, Compounds and Mixtures

• Element: made of one type of atom.

• Compound: two or more elements chemically combined.

• Mixture: substances physically combined.

Atom

• Proton – positive charge

• Electron – negative charge

• Neutron – no charge

• Protons and neutrons are present in the nucleus.

Acids, Bases and Salts

• Acids generally have a sour taste.

• Bases generally feel soapy/slippery.

• pH < 7: acidic

• pH = 7: neutral

• pH > 7: basic

• Acid + Base → Salt + Water

Metals and Non-metals

Metals:

• Generally lustrous

• Good conductors of heat and electricity

• Usually malleable and ductile

Non-metals:

• Generally poor conductors

• Usually brittle when solid

• Many are gases at room temperature

Physical and Chemical Changes

• Physical change: no new substance is formed.

• Chemical change: one or more new substances are formed.

• Rusting of iron is a chemical change.

3. Biology

Cell

• The cell is the basic structural and functional unit of life.

• Nucleus controls many cellular activities.

• Mitochondria are associated with energy production.

• Chloroplasts are found in green plant cells and carry out photosynthesis.

• Cell wall provides support to plant cells.

Human Body

Digestive System

Main organs:
Mouth → Oesophagus → Stomach → Small Intestine → Large Intestine → Rectum → Anus

• Digestion begins in the mouth.

• Most absorption of digested nutrients occurs in the small intestine.

Respiratory System

• Main organs include the nose, trachea, bronchi and lungs.

• Exchange of oxygen and carbon dioxide occurs mainly in the alveoli.

Circulatory System

• The heart pumps blood throughout the body.

• Blood contains RBCs, WBCs, platelets and plasma.

• RBCs contain haemoglobin, which helps transport oxygen.

• WBCs help defend the body against infections.

• Platelets help in blood clotting.

Excretory System

• The kidneys filter the blood and help form urine.

• The basic functional unit of the kidney is the nephron.

Nervous System

• The brain, spinal cord and nerves form the major parts of the nervous system.

• The brain coordinates and controls many body activities.

• Neurons transmit nerve impulses.

4. Plant Science

Photosynthesis

Green plants prepare food using:

• Carbon dioxide

• Water

• Sunlight

• Chlorophyll

Oxygen is released during photosynthesis.

Plant Tissues

• Xylem: transports water and minerals.

• Phloem: transports prepared food.

Reproduction in Plants

• Pollination is the transfer of pollen from anther to stigma.

• Pollination may be self-pollination or cross-pollination.

• Fertilization leads to the formation of a zygote.

5. Health and Diseases

Communicable Diseases

Diseases that can spread from one person to another are called communicable diseases.

Examples:

• Tuberculosis

• Measles

• Cholera

• Malaria

• Dengue

Deficiency Diseases

Balanced Diet

A balanced diet provides appropriate amounts of:
carbohydrates, proteins, fats, vitamins, minerals, fibre and water.

6. Environment and Ecology

Ecosystem

An ecosystem consists of living organisms and their physical environment.

• Producers: green plants

• Consumers: animals

• Decomposers: bacteria and fungi

Food Chain

A food chain represents the transfer of food and energy from one organism to another.

Example:
Grass → Grasshopper → Frog → Snake → Eagle

Pollution

Major types:

• Air pollution

• Water pollution

• Soil pollution

• Noise pollution

Greenhouse Effect

Certain gases trap heat in the Earth’s atmosphere. Important greenhouse gases include:

• Carbon dioxide

• Methane

• Nitrous oxide

• Water vapour

Ozone Layer

• The ozone layer protects Earth from harmful ultraviolet (UV) radiation.

• Ozone is composed of O₃.

7. Important Science One-Liners

• Basic unit of life → Cell

• Powerhouse of cell → Mitochondria

• Green pigment in plants → Chlorophyll

• Largest human organ → Skin

• Largest internal organ → Liver

• Functional unit of kidney → Nephron

• Functional unit of nervous system → Neuron

• Universal donor blood group → O negative

• Universal recipient blood group → AB positive

• Normal human body temperature → about 37°C

• Gas essential for respiration → Oxygen

• Gas used by plants in photosynthesis → Carbon dioxide

• Chemical formula of water → H₂O

• Chemical formula of carbon dioxide → CO₂

• Common salt → Sodium chloride (NaCl)

• SI unit of force → Newton

• SI unit of energy → Joule

• SI unit of power → Watt

• SI unit of electric current → Ampere

• Speed of light in vacuum → approximately 3 × 10⁸ m/s

KREIS Exam 2026 – Most Important Areas

For quick preparation, give special attention to:

Physics: Motion, Force, Work & Energy, Heat, Light, Sound, Electricity and Magnetism

Chemistry: Matter, Atom, Elements, Compounds, Acids-Bases-Salts, Metals & Non-metals, Chemical Reactions

Biology: Cell, Human Body Systems, Nutrition, Diseases, Plant Biology, Reproduction and Genetics

Environment: Ecosystem, Food Chain, Biodiversity, Pollution, Climate Change, Natural Resources and Conservation

Health Science: Balanced Diet, Vitamins, Deficiency Diseases, Communicable Diseases, First Aid and Personal Hygiene