GCSE Physics Practical Experiments: IR Emission, Water Properties, Density, and Resistance of a Wire

A complete set of vocabulary flashcards covering key definitions, formulas, variables, and experimental setups from the GCSE Physics practical notes.

Leslie cube

A hollow metal cube filled with hot water from a freshly-boiled kettle, used to measure the relative emission of IR radiation from different surface finishes.

Matte black surface properties

The surface finish that acts as the best absorber AND the best emitter of IR radiation.

Shiny surface properties

The surface finish that is the worst at both absorbing AND emitting IR radiation.

Distance control in IR radiation experiments

The practice of using a ruler to ensure the distance between the surface and the IR detector or IR lamp remains constant as a control variable.

Infra-red emission and absorption experimental setups

Investigations measuring IR emission from a Leslie cube using an IR detector, and IR absorption using wrapped boiling tubes placed at equal distance from an IR lamp.

Specific Heat Capacity (SHC) equation

The formula used to calculate SHC, given by $\text{SHC} = \frac{\text{energy}}{\text{mass} \times \text{temp change}}$.

True SHC of water

The accepted value for the specific heat capacity of water, which is $4200\text{J/kg}^\text{o}\text{C}$.

Electrical energy supplied equation

The calculation for energy supplied to a heater defined as $\text{energy} = \text{Power} \times \text{time} = V \times I \times t$, where voltage $V$ is measured using a voltmeter in parallel and current $I$ using an ammeter in series.

Specific Latent Heat (SLH) equation

The formula used to calculate SLH, given by $\text{SLH} = \frac{\text{energy}}{\text{mass}}$.

True SLH of fusion of water

The accepted value for the specific latent heat of fusion of water, which is $334000\text{J/kg}$.

Thermal insulation in heat experiments

Material placed around experimental setups to reduce energy transferred to surroundings.

Water properties experimental apparatus

Setups used to measure thermal properties of water, including an electrical heater in water with a voltmeter and ammeter, and crushed ice melting in a funnel over a beaker.

Density equation

The formula defined as $\text{density} = \frac{\text{mass}}{\text{volume}}$, measured in $\text{g/cm}^3$ when mass is measured in $\text{g}$ and volume in $\text{cm}^3$.

Top-pan balance

An instrument used to measure the mass of solid objects or solutions in density investigations.

Regular object volume determination

The process of measuring the dimensions (height, length, and width) of a regular object using a ruler or Vernier calliper and calculating its volume from these measurements.

Displacement ('Eureka') Can

A container used to lower an irregular object into water so that the volume of water displaced into a measuring cylinder can be measured.

Meniscus

The curved upper surface of a liquid, which must be read at eye level when using a measuring cylinder to obtain an accurate volume.

Concentration calculation from density

The method of finding solution concentration by subtracting the density of pure water ($1\text{g/cm}^3$) from the overall density of the solution (e.g. $1.2\text{g/cm}^3 - 1\text{g/cm}^3 = 0.2\text{g/cm}^3$).

Density determination methods apparatus

Equipment set-ups for measuring mass and volume of regular solids, irregular solids using a displacement can, and liquid solutions using a zeroed measuring cylinder.

Constantan wire

A specific type of wire whose resistance does not change significantly with temperature, making it ideal for testing how length affects resistance.

Variables in the wire resistance investigation

The experiment where the independent variable is length of wire, the dependent variable is resistance of wire, and the control variables are thickness and type of wire.

Ohm's Law equation

The relationship defined as $V = I \times R$, which rearranges to $R = \frac{V}{I}$ to determine resistance from measured potential difference and current.

Resistance and wire length relationship

A directly proportional relationship indicated by a straight/linear line of best fit (LOBF) that passes through the origin when plotting resistance against length.

Resistance of a wire experimental setup

A circuit setup containing constantan wire attached by crocodile clips across a metre rule, connected with an ammeter in series and a voltmeter in parallel.