LDR (light dependent resistance) can be very easily tested by using a digital multimeter. We all know that the resistance of an LDR varies according to the light falling on it. At bright light, the LDR resistance will be around 500Ohms and at darkness the resistance will be around 200K. For a proper diagnosis we need to measure the resistance of the LDR at bright light and at darkness.
Test1.
Keep the multimeter at Ohms mode. The LDR must be subjected to a bright light source (day light is enough).Connect the LDR leads to the multimeter terminals as shown in the figure. Now the multimeter will show a low resistance reading around 500 Ohms.
Test2.
Keep the multimeter at Ohms mode. The LDR must be subjected to darkness by covering it with an opaque paper. Connect the LDR leads to the multimeter terminals as shown in the figure. Now the multimeter will show a high resistance reading around 200K.
If both of the above tests are positive then we can conclude that the LDR is healthy.
12 Comments
KK
This was very useful for my Physics ISA! Ignore the comments from my good friend Nigel and Adolf.
safeum fam, if u want gear giv us a bell broski, ya nans on dat baked beanz ting
tis was rely hepful fanks you for heping meh u very kynd
Thank You.
your welcome
very helpful indeed.
will u plz reply to my questions which i sent through my mail?
thnku! can i please get this as my refernce? problem is I don’t know if whose the author and publisher and all things that need to be iclude when u write a referece. can you pls give me those? and also the copyright, title of page etc. thnku so much! God bless u!
thnxx soooooooo much …….God bless you
thank you very much . .