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A L.D.R is a light dependant resistor
A photo resistor or Light Dependent Resistor or CDS Cell is an electronic component whose resistance decreases with increasing incident light intensity. It can also be referred to as a photo conductor.
A photo resistor is made of a high resistance semiconductor. If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band. The resulting free electron (and its hole partner) conduct electricity, thereby lowering resistance.
A photoelectric device can be either intrinsic or extrinsic. An intrinsic semiconductor has its own charge carriers and is not an efficient semiconductor, egg. silicon. In intrinsic devices, the only available electrons are in the valence band, and hence the photon must have enough energy to excite the electron across the entire band gap. Extrinsic devices have impurities added, which have a ground state energy closer to the conduction band - since the electrons don't have as far to jump, lower energy photons (i.e. longer wavelengths and lower frequencies) are sufficient to trigger the device. If a sample of silicon has some of its atoms replaced by phosphorus atoms(impurities), there will be extra electrons available for conduction.
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How does light affect LDR?
An LDR is a light dependent resistor, which is usually used to detect light levels, either ambient or reflected. The LDR works because incoming light carries energy, which can elevate the energy levels of electrons in a suitable medium to join the 'conduction band' which means that there are more charge carriers in the LDR, and hence the cell has lower resistance.
What does an LDR cost?
about 13 p each but would be cheaper if bought together
When an LDR detects light or dark how long does it take for its resistance to change?
20 seconds
What is the function of an LDR or a TDR in an circuit?
The function of an LDR or light dependent resistor is to change the brightness of the light based weather conditions or light hitting the object the LDR is on. When it is darker out, the light does not shine as brightly.
What is the advantage of including a variable resistor rather than a fixed resistor of know size in a potential divider that includes and LDR or a thermistor?
a three prong calisator with intermittent interphase
What is the symbol for ldr?
this is the symbol for ldr
What is an LDR symbol?
An LDR is a Light dependent resistor.
What is the meaning of LDR?
LDR refers to Light Dependent Resistor.
What is the symbol for LDR Holding Corporation in NASDAQ?
The symbol for LDR Holding Corporation in NASDAQ is: LDRH.
What does LDR stand for?
Light Dependent Resistor LDR also means long distance relationship.
In what year did LDR Holding Corporation - LDRH - have its IPO?
LDR Holding Corporation (LDRH) had its IPO in 2013.
What happens to an LDR when a bright light is shined upon it?
When LDR is exposed to light energy . Due to light energy incident on LDR surface, free electron movement of an atom is increased in LDR. This causes high conduction of curent flowing through LDR. beause of free electron movement in LDR, resitance get decreased.
What does a LDR sense?
light
What is the purpose of LDR on a circuit?
158980
What is the market cap for LDR Holding Corporation LDRH?
As of July 2014, the market cap for LDR Holding Corporation (LDRH) is $534,318,199.51.
How does light affect LDR?
An LDR is a light dependent resistor, which is usually used to detect light levels, either ambient or reflected. The LDR works because incoming light carries energy, which can elevate the energy levels of electrons in a suitable medium to join the 'conduction band' which means that there are more charge carriers in the LDR, and hence the cell has lower resistance.
Where in the cell does the LDR take place?
photosynthesis
