- Physics Lab Equipment
- Chemistry Lab Equipment
- Biology Lab Equipment
- Anatomical Lab Equipment
- Learning
- Educational Lab Equipment
- Magnets
- Agriculture
- Astronomy
- Earth Science
- Geography Lab Equipment
- Safety Lab Coat
- Laboratory
- Meteorological
- Electricity & Magnetism
- Heat
- School Lab Equipment
- Lab Glassware
- Science Lab Equipment
- Tvet Lab Equipment
- Robotics Kits Supplier and Manufacturer for Schools India
- Math Lab Equipment Manufacturers and Exporters in Ambala
- STEM Kits Manufacturers and Supplier India
- Engineering Lab Equipment
- Hospital Lab Equipment
- Water, Sanitation & Hygiene Supplies
- Cold Chain, Solar & Communication Equipment
- Nutrition
Light Dependent Resistor
Light Dependent Resistor (Product Code: SLE/PHY/71) is a cadmium sulphide (CdS) photoconductive cell used to sense light levels in school electronics circuits, physics practicals and student projects. Its resistance falls as more light reaches it, from a dark resistance of 1 MΩ, and its spectral response is similar to that of the human eye. It is supplied by Jain Scientific Equipments Pvt Ltd (ScienceLab), Ambala, India, as a component for school physics lab equipment in India and international markets.
Specifications
| Parameter | Detail |
|---|---|
| Type | Cadmium sulphide (CdS) photoconductive cell |
| Housing | Robust clear plastic package with clear end window; moisture-resistant coating |
| Top dimensions | 14.35 × 7 mm (diameter × depth) |
| Pin length | 9.53 mm |
| Dark resistance | 1 MΩ |
| Resistance at 1 ftc (foot-candle) | 5.4 kΩ min, 12.6 kΩ max |
| Maximum voltage | 250 V peak, AC or DC |
| Power dissipation | 250 mW max |
| Operating temperature | −60 °C to +75 °C |
| Spectral response | Similar to that of the human eye |
| Behaviour | Resistance reduces as the light falling on the LDR increases |
| Product code | SLE/PHY/71 |
| Supplied by | Jain Scientific Equipments Pvt Ltd (ScienceLab), Ambala, India |
What Is a Light Dependent Resistor Used For?
In class, the LDR is usually wired in series with a fixed resistor to form a voltage divider, so the output voltage changes with light level. That simple arrangement is the basis of automatic night lights, light meters and burglar-alarm circuits that students build in electronics lessons. It is a standard part in OPTO electronics experiment kit work alongside LEDs and phototransistors.
For a quick demonstration, connect the LDR to a multimeter on its resistance range and let students cover it, uncover it and move a lamp closer while they note the readings. Because its response is similar to the human eye, results relate well to how bright a room looks. Bend the pins gently near the body, and keep power dissipation well under the 250 mW limit.
What to Specify When Ordering
- Quantity of LDRs needed for the class or project
- Whether you want the bare component or the board-mounted Simple Circuit Module version
- Any meters or light sources to be quoted with them
Supplier
ScienceLab is the trading name of Jain Scientific Equipments Private Limited, which sources and supplies electronic components such as this light dependent resistor alongside its physics apparatus range. Schools, colleges and dealers can add LDRs to a wider laboratory order and receive a single quotation. Company details are on the ScienceLab profile page.
Related Physics Lab Equipment
These items are used with an LDR in light-sensing experiments:
- Simple Circuit Module Light Dependent Resistor Board — an LDR ready-mounted on a module board
- LED, 5 mm, White — a small light source for LDR response tests
- Standard Digital Multimeter — to read the LDR's resistance as light changes
- Crocodile Clips & Leads — to connect the LDR pins without soldering
- Light Energy Kit — for wider lessons on light as a form of energy
Browse more items in Physics Lab Equipment.
Frequently Asked Questions
What is the dark resistance of this Light Dependent Resistor?
The Light Dependent Resistor has a dark resistance of 1 MΩ, and at an illumination of 1 foot-candle its resistance lies between 5.4 kΩ and 12.6 kΩ. Brighter light lowers the resistance further, which is what makes it useful as a light sensor.
What are the maximum ratings of the Light Dependent Resistor?
The Light Dependent Resistor is rated for a maximum of 250 V peak AC or DC and 250 mW power dissipation, with an operating temperature range of −60 °C to +75 °C. School circuits normally run it far below these limits from low-voltage cells.
Is the LDR protected against moisture?
Yes, this Light Dependent Resistor is encapsulated in a moisture-resistant coating and enclosed in a robust clear plastic package with a clear end window. Keep it dry and wipe the window gently so dust does not reduce the light reaching the sensing surface.
What size is the Light Dependent Resistor?
The Light Dependent Resistor's top measures 14.35 × 7 mm (diameter × depth) and its pins are 9.53 mm long. The pins can be connected with crocodile leads for classroom circuits or soldered into a permanent project board.
Who supplies the Light Dependent Resistor?
The Light Dependent Resistor is supplied by Jain Scientific Equipments Pvt Ltd, trading as ScienceLab, from Ambala, Haryana, India. It is a sourced electronic component that the company adds to school and college orders together with circuit boards, meters and other physics items.
How do I get a quotation for LDRs?
To get a quotation for the Light Dependent Resistor, send the quantity you need and your delivery location through the contact page or the enquiry cart. Mention if you also want the board-mounted LDR module or meters, so everything can be quoted together.
Request a Quote
Ask for a price on the Light Dependent Resistor through the contact page, or add it to the enquiry cart with any other items for your lab.
Last updated: 24 September 2026
