IndiaBIX

Electronics and Communication Engineering - Electronic Devices and Circuits - Discussion

Discussion Forum : Electronic Devices and Circuits - Section 1 (Q.No. 10)
Electronic Devices and Circuits
10.
In the circuit of figure the function of resistor R and diode D are
to limit the current and to protect LED against over voltage
to limit the voltage and to protect LED against over current
to limit the current and protect LED against reverse breakdown voltage.
none of the above.
Answer: Option
Explanation:

Resistance limits current and diode is reverse connected and therefore protects LED against reverse breakdown.

Discussion:
14 comments Page 1 of 2.
Bhagya sri said:   9 years ago
Can anyone please give little more clarification to this question?
(1)
Reena said:   7 years ago
Is this zener diode or else?
(1)
Abi said:   3 years ago
How it works? Please explain.
(1)
Aayan said:   1 decade ago
I have a question how diode protect the led?
Aman said:   1 decade ago
Diode is in reverse bias when input voltage become more then breakdown for LED. Diode D becomes short circuit and bypass the current so LED protected.
SUKHVIR SINGH said:   1 decade ago
When led under reverse bias D is forward bias. So current find he path through D. Hence led is protected.
Abhishek said:   1 decade ago
Thanks for explanation.
Kalakal said:   9 years ago
I accept your point @Aman.
Ruchi said:   9 years ago
The gain in cc mode is 1/(1- a).
Ali Waqas said:   9 years ago
If the input voltage is dangerously increased (up to breakdown voltage) then diode will start conducting and thus be protecting the LED.
Post your comments here:

Your comments will be displayed after verification.

Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers