Common Practical Topics (Copy)

 

• Objective of the experiment
• Apparatus required
• Method summary
• Equations used
• Graphical skills (if applicable)
• Common errors
• Exam tips

These experiments reflect real-school physics practicals adapted for ATP assessment.

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1. Length, Time, and Speed

 Objective:

• Measure distances, time intervals, and calculate speed or average speed.

 Apparatus:

• Metre rule / measuring tape
• Stopwatch / digital timer
• Light gates and ticker timer (advanced)

Method:

• Measure distance (in m) between two points.
• Use stopwatch to measure time (in s) for object to travel that distance.
• Calculate:
  Speed = distance / time

Common Errors:

• Reaction time delay in manual timing
• Starting/stopping stopwatch too early/late
• Measuring distance inaccurately

Tips:

• Repeat readings and take average time
• Ensure eye level with scale for distance
• Use light gates if asked to reduce human error

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2. Mass, Volume, and Density

 Objective:

• Calculate density using mass and volume.

Apparatus:

• Balance (digital)
• Ruler / Vernier caliper / Micrometer
• Measuring cylinder
• Eureka (displacement) can
• Irregular and regular solids

 Method:

1. Measure mass (g or kg) using digital balance.
2. Measure volume:
   • Regular object: use formula (e.g., cube = l × w × h)
   • Irregular: use water displacement method

Equation:

Density = mass / volume
Units: kg/m³ or g/cm³

Tips:

• Convert all values to consistent units
• Read volume at eye level to avoid parallax
• Remove air bubbles when using displacement

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3. Forces and Newton’s Laws

 Objective:

• Investigate effect of force on motion or extension.

 Apparatus:

• Trolley, masses, string, pulley, stopwatch
• Newton-meter (spring balance)

 Method (Trolley on Ramp):

• Vary pulling force (via hanging mass)
• Measure time for trolley to move fixed distance
• Use: acceleration = change in speed / time

 Tips:

• Ensure friction is minimal (e.g., smooth surface)
• Keep ramp angle constant
• Take multiple time readings and average

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 4. Moments (Turning Effect of Forces)

 Objective:

• Verify principle of moments (clockwise moment = anticlockwise moment)

 Apparatus:

• Metre rule (pivoted at center)
• Weights and hangers
• Clamp stand and pivot

 Method:

• Hang weights at known distances from pivot
• Adjust positions until beam is horizontal
• Calculate: Moment = force × perpendicular distance

 Tips:

• Force = weight = mass × g
• Measure distances from pivot only
• Ensure metre rule is balanced horizontally

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 5. Hooke’s Law (Stretching of Springs)

 Objective:

• Investigate relationship between force and extension.

 Apparatus:

• Clamp stand, spring, weights, metre rule

 Method:

• Add known masses to spring
• Measure extension (new length – original length)
• Plot Force (N) vs Extension (cm)

 Equation:

F = k × x
→ k = spring constant (gradient of graph)

 Tips:

• Keep spring vertical
• Use pointer for accurate reading
• Plot straight-line graph through origin = obeys Hooke’s Law

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 6. Thermal Experiments

 Objective:

• Investigate heat loss, temperature change, or heat capacity.

 Apparatus:

• Thermometer, beaker, heater, insulators, stopwatch

 Method:

• Heat known mass of water or metal
• Record temperature at regular time intervals
• For cooling: insulate and monitor temp drop

 Equation:

E = mcΔT
→ E = heat energy, m = mass, c = specific heat, ΔT = temp change

 Tips:

• Stir water for uniform heating
• Use lid and insulation to reduce heat loss
• Measure mass using digital balance

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 7. Electrical Circuits (V-I Experiments)

 Objective:

• Investigate relationship between voltage and current.

 Apparatus:

• Power supply, resistor/wire, ammeter, voltmeter, switch

 Method:

• Connect resistor in circuit
• Vary voltage (using variable resistor or different cells)
• Record V and I values
• Plot V vs I graph

 Equation:

V = I × R
→ Gradient = resistance

 Tips:

• Ammeter in series, voltmeter in parallel
• Switch off between readings (avoid heating)
• Ensure readings are steady before recording

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 8. Resistance of a Wire

 Objective:

• Investigate how wire length affects resistance.

 Apparatus:

• Constantan/nichrome wire, ruler, ammeter, voltmeter, power source

 Method:

• Connect different lengths of wire in circuit
• Measure voltage and current
• Calculate resistance: R = V/I
• Plot R vs Length

 Tips:

• Keep wire straight and tight on ruler
• Use same material and thickness
• Avoid overheating wire

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 9. Reflection and Refraction

 Objective:

• Measure angles of incidence/reflection/refraction

 Apparatus:

• Ray box, mirror/glass block, protractor, paper

 Method (Reflection):

• Shine ray onto plane mirror
• Measure angle of incidence and angle of reflection

Method (Refraction):

• Shine ray through glass block
• Measure i and r, then calculate:
  n = sin(i) / sin(r)

Tips:

• Draw normal with ruler at 90°
• Use sharp pencil rays
• Label i, r, normal, and boundary

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 10. Lenses and Image Formation

 Objective:

• Find focal length of convex lens

 Apparatus:

• Lit object (candle or lamp), convex lens, screen, ruler

 Method:

• Place object at various distances
• Move screen to get sharp image
• Measure u (object distance) and v (image distance)

Use formula:
1/f = 1/u + 1/v

 Tips:

• Align lens, object, and screen on optical bench
• Record multiple (u, v) pairs and average f

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 11. Motion and Acceleration

 Objective:

• Measure acceleration of a moving object

 Apparatus:

• Ramp, trolley, stopwatch or light gates, metre rule

 Method:

• Let trolley roll down ramp
• Measure time for fixed distance or use light gates to measure speed at intervals
• Calculate acceleration:
  a = (v - u) / t

 Tips:

• Use same starting height for ramp
• Keep track of friction or surface texture
• Use ticker tape timer if available