Physics — Study Notes for AP TET Paper II
Overview
Physics forms a core component of the Mathematics and Science section in AP TET Paper II, targeting teachers for classes 6–8. This section tests your understanding of fundamental physical concepts that upper primary students encounter — force, motion, energy, heat, light, sound, electricity and magnetism.
Questions typically test conceptual clarity rather than complex numerical calculations. You must understand everyday applications of physics principles, as NCF 2005 emphasises connecting science to daily life experiences. Strong command over basic definitions, SI units, simple formulas and cause-effect relationships is essential for scoring well.
The pedagogy aspect expects you to know how to teach these concepts through activities, demonstrations and experiments suitable for young learners.
Key Concepts
- Force is a push or pull that changes an object's state of rest or motion. It has both magnitude and direction (vector quantity). SI unit is Newton (N).
- Friction is the force that opposes relative motion between surfaces in contact. It can be useful (walking, writing) or harmful (wear and tear). Types: static, sliding and rolling friction.
- Motion is change in position of an object with time. Types include rectilinear (straight line), circular, oscillatory and random motion.
- Work is done when force causes displacement. Work = Force × Displacement × cos θ. SI unit is Joule (J). No work is done if displacement is zero or force is perpendicular to displacement.
- Energy is the capacity to do work. Forms include kinetic, potential, heat, light, sound, electrical and chemical energy. Energy can be transformed but not created or destroyed (Law of Conservation of Energy).
- Heat is energy transferred due to temperature difference. It flows from hotter to colder body. Modes of transfer: conduction, convection and radiation.
- Light travels in straight lines (rectilinear propagation). Reflection occurs when light bounces off a surface. Refraction is bending of light when it passes from one medium to another.
- Sound is produced by vibrations and needs a material medium to travel. It cannot travel through vacuum. Speed of sound: solid > liquid > gas.
- Electric current is flow of electric charges through a conductor. SI unit is Ampere (A). A complete circuit is needed for current to flow.
- Magnets have two poles — north and south. Like poles repel, unlike poles attract. Earth behaves like a giant magnet.
Formulas / Key Facts
| Concept | Formula / Fact |
|---|---|
| Speed | Speed = Distance ÷ Time (m/s) |
| Velocity | Displacement ÷ Time (vector, has direction) |
| Acceleration | Change in velocity ÷ Time (m/s²) |
| Work | W = F × d (when force and displacement are in same direction) |
| Kinetic Energy | KE = ½ × m × v² |
| Potential Energy | PE = m × g × h |
| Power | Power = Work ÷ Time; SI unit is Watt (W) |
| Ohm's Law | V = I × R (Voltage = Current × Resistance) |
| Speed of light | 3 × 10⁸ m/s in vacuum |
| Speed of sound in air | Approximately 340 m/s at room temperature |
| Angle of incidence | Equals angle of reflection (Law of Reflection) |
| Boiling point of water | 100°C at normal atmospheric pressure |
Worked Examples
Example 1: Calculating Work Done
A boy pushes a box with a force of 50 N and moves it 4 m in the direction of force. Calculate work done.
Solution:
- Work = Force × Displacement
- Work = 50 N × 4 m = 200 J
The work done is 200 Joules.
Example 2: Ohm's Law Application
A torch bulb has resistance 5 Ω and current of 0.4 A flows through it. Find the voltage of the cell.
Solution:
- V = I × R
- V = 0.4 A × 5 Ω = 2 V
The voltage of the cell is 2 Volts.
Example 3: Speed Calculation
A car travels 150 km in 3 hours. What is its average speed?
Solution:
- Speed = Distance ÷ Time
- Speed = 150 km ÷ 3 h = 50 km/h
Average speed is 50 kilometres per hour.
Common Mistakes
❌ Confusing mass and weight → Mass is amount of matter (kg), weight is gravitational force on mass (N). Weight = mass × g.
❌ Thinking sound travels fastest in air → Sound actually travels fastest in solids, slowest in gases. Particles are closest in solids, enabling faster transmission.
❌ Assuming work is done whenever force is applied → No work is done if there is no displacement, or if force is perpendicular to displacement (e.g., carrying a bag while walking horizontally).
❌ Believing heat and temperature are the same → Heat is energy transferred; temperature is measure of hotness/coldness. A cup of tea at 80°C has less heat than a bucket of water at 60°C.
❌ Thinking current is "used up" in a circuit → Current remains same throughout a series circuit. Energy is transferred, not current.
❌ Confusing real and virtual images → Real images can be caught on screen (formed by converging rays); virtual images cannot (formed by diverging rays).
Quick Reference
- Force changes state of rest or motion; measured in Newtons.
- Work = Force × Displacement; no displacement means no work.
- Energy transforms but total energy remains conserved.
- Heat transfers by conduction, convection and radiation.
- Light: angle of incidence = angle of reflection.
- Sound needs medium; travels fastest in solids.
- Ohm's Law: V = I × R — fundamental for electric circuits.
- Like magnetic poles repel; unlike poles attract.