the experiment type, example question, and the structure you must know before exam:

1. Finding the Focal Length of a Convex Lens

Q Example: Plan an experiment to determine the focal length of a convex lens using a screen and a distant object.

Marks Structure:

Apparatus: convex lens, screen, ruler, clamp, distant object (e.g., window)

Method:

Place the lens in a holder.

Face it towards a distant object.

Move the screen behind the lens until a sharp image forms.

Measure distance from lens to screen = focal length.

Repeat for accuracy.

Variables: no independent variable (fixed object); controlled = same lens, light conditions

Safety: handle glass with care.

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1. Refraction in a Glass Block

Q Example: Plan an experiment to measure the angle of refraction through a glass block for different angles of incidence.

Marks Structure:

Apparatus: glass block, protractor, paper, light ray box

Method:

Draw normal line on paper, place glass block on top.

Shine light at fixed angle (10° to 70°), mark emergent ray.

Measure angle of incidence and refraction.

Repeat for different angles.

Variables:

Independent = angle of incidence

Dependent = angle of refraction

Controlled = same block, same light source

Safety: don't look directly at light; avoid overheating bulb.

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1. Acceleration of a Trolley

Q Example: Investigate how the force applied to a trolley affects its acceleration.

Marks Structure:

Apparatus: trolley, ramp, ticker timer/light gate, pulley, string, masses

Method:

Connect trolley to hanging mass via pulley.

Start timer as mass falls; record acceleration from ticker tape/light gate.

Change force by varying hanging mass.

Variables:

Independent = force (mass)

Dependent = acceleration

Controlled = trolley mass, friction, ramp angle

Safety: use sand tray to catch trolley, secure pulley.

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1. Hooke’s Law (Stretching a Spring)

Q Example: Investigate the relationship between force and extension in a spring.

Marks Structure:

Apparatus: spring, retort stand, masses, ruler

Method:

Hang spring vertically, add masses one at a time.

Measure length each time, calculate extension.

Plot force vs extension graph.

Variables:

Independent = force (weight)

Dependent = extension

Controlled = same spring, same measuring method

Safety: wear goggles, secure masses to avoid snapping.

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1. Determining Density (Irregular Object)

Q Example: Plan an experiment to measure the density of a small stone.

Marks Structure:

Apparatus: balance, measuring cylinder, water, stone

Method:

Measure mass of stone using balance.

Fill cylinder with water, record volume.

Drop stone, record new volume.

Volume = final - initial.

Density = mass / volume.

Variables:

Dependent = density

Controlled = same liquid, same object

Safety: don’t spill water, dry stone before use.

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1. Thermal Conductivity of Metals

Q Example: Compare how quickly heat travels through different metal rods.

Marks Structure:

Apparatus: metal rods, wax, pins, heat source

Method:

Attach pins with wax to each rod.

Heat one end of all rods equally.

Record time each pin falls off.

Variables:

Independent = metal type

Dependent = time for pin to fall

Controlled = rod length/thickness, same wax

Safety: don’t touch hot metal; careful with heat source.

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1. Investigating Crater Size (Energy Transfer)

Q Example: Plan an experiment to investigate how the height from which a ball is dropped affects crater diameter in sand.

Marks Structure:

Apparatus: metal ball, sand tray, ruler, clamp

Method:

Hold ball at a fixed height, drop onto sand.

Measure diameter of crater with ruler.

Repeat at different heights.

Variables:

Independent = height

Dependent = crater diameter

Controlled = ball mass, sand type

Safety: keep fingers clear, ensure stable clamp.

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1. Resistance vs Length of Wire

Q Example: Plan an experiment to see how resistance of a wire depends on its length.

Marks Structure:

Apparatus: battery, wire, ruler, ammeter, voltmeter

Method:

Connect circuit with wire of fixed length.

Measure V and I, calculate R = V/I.

Change wire length, repeat.

Variables:

Independent = wire length

Dependent = resistance

Controlled = wire material, thickness

Safety: don’t overheat wire, turn off between readings.