Practical Activity: Inverse Square Law
Practical Activity - Inverse Square Law Covering 3.4 and 3.7
Aim: How is the intensity of light affected by distance?
Equipment: Transformer, Digital light meter, 1 meter ruler, banana clips, Light bulb
Risk Assessment
Identify Rating Minimisation
Electrocution Low Do not touch leads which are not covered by insulating material and tuck wires not in use safely away, make sure PowerPoint is in suitable condition
Bright light damaging eyes Low Keep voltage of transformer low, 10-12 and do not continuously stare at the light
Procedure
1. Obtain school transformer, digital light meter and a 1 meter ruler
2. Turn the transformer to DC
3. Plug in the banana and alligator clips (leads) into the transformer, negative DC outlet …show more content…
The shape of the graph 1/d^2 is a downwards exponential graph and represents a curve, the shape of the graph is downwards exponential and a curve due to numbers being squared, this squaring of numbers and numbers with even indices creates a curve or an exponential graph.
Explain what are the units for light intensity(how much light falls on a meter by a meter squared)
The intensity of light (E.M.R) is a measure of the energy per unit area, the intensity decreases greatly with a small change with the distance. The units that are used to measure light intensity are Lux.
What is Lux? How much light falls into an area in Lux?
Lux is the unit of luminance , measuring light intensity per unit area. The amount of light that falls into an area of lux is equal to one lumen per square metre. Hence, if an area of 1m² is lit up by 1000 lumens, the intensity of illumination will be 1000 Lux. If an area of 10m² is lit up by 1000 lumens, the intensity will be 100 …show more content…
The light that falls onto the sensor or even a photo cell contains energy, this energy is then converted to an electric current. In turn, the amount of current depends on the amount of light that strikes the photo cell or light sensor. Lux meters read the electrical current, calculate the appropriate value, and output the results to an analog, digital, or video display. Since light usually contains different colours at different wavelengths, the reading represents the combined effects of all the wavelengths.
Light meters have many use daily situations for many people, businesses and groups around the world. Light meters are used to measure levels of light in schools, hospitals, production areas, laboratories, and passageways. They are also used to monitor light-sensitive displays in museums, art galleries and archives. meter is often used to determine the proper levels of exposure for a photograph, this can then be worked with and allows the photographer to determine which shutter speed ,light meters are vital in photography. They are also used in the general field of lighting, where they can help to reduce the amount of waste light used in the home, light pollution outdoors, and plant growing to ensure proper light levels. Light meters are also used in the fields of cinematography and scenic design, in order to determine the optimum light level for
Aim: How is the intensity of light affected by distance?
Equipment: Transformer, Digital light meter, 1 meter ruler, banana clips, Light bulb
Risk Assessment
Identify Rating Minimisation
Electrocution Low Do not touch leads which are not covered by insulating material and tuck wires not in use safely away, make sure PowerPoint is in suitable condition
Bright light damaging eyes Low Keep voltage of transformer low, 10-12 and do not continuously stare at the light
Procedure
1. Obtain school transformer, digital light meter and a 1 meter ruler
2. Turn the transformer to DC
3. Plug in the banana and alligator clips (leads) into the transformer, negative DC outlet …show more content…
The shape of the graph 1/d^2 is a downwards exponential graph and represents a curve, the shape of the graph is downwards exponential and a curve due to numbers being squared, this squaring of numbers and numbers with even indices creates a curve or an exponential graph.
Explain what are the units for light intensity(how much light falls on a meter by a meter squared)
The intensity of light (E.M.R) is a measure of the energy per unit area, the intensity decreases greatly with a small change with the distance. The units that are used to measure light intensity are Lux.
What is Lux? How much light falls into an area in Lux?
Lux is the unit of luminance , measuring light intensity per unit area. The amount of light that falls into an area of lux is equal to one lumen per square metre. Hence, if an area of 1m² is lit up by 1000 lumens, the intensity of illumination will be 1000 Lux. If an area of 10m² is lit up by 1000 lumens, the intensity will be 100 …show more content…
The light that falls onto the sensor or even a photo cell contains energy, this energy is then converted to an electric current. In turn, the amount of current depends on the amount of light that strikes the photo cell or light sensor. Lux meters read the electrical current, calculate the appropriate value, and output the results to an analog, digital, or video display. Since light usually contains different colours at different wavelengths, the reading represents the combined effects of all the wavelengths.
Light meters have many use daily situations for many people, businesses and groups around the world. Light meters are used to measure levels of light in schools, hospitals, production areas, laboratories, and passageways. They are also used to monitor light-sensitive displays in museums, art galleries and archives. meter is often used to determine the proper levels of exposure for a photograph, this can then be worked with and allows the photographer to determine which shutter speed ,light meters are vital in photography. They are also used in the general field of lighting, where they can help to reduce the amount of waste light used in the home, light pollution outdoors, and plant growing to ensure proper light levels. Light meters are also used in the fields of cinematography and scenic design, in order to determine the optimum light level for