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Electronics — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsElectronics1 Mark
Question
Assertion : Two $P-N$ junction diodes placed back to back, will work as a NPN transistor.
Reason : The $P$-region of two $P N$ junction diodes back to back will form the base of NPN transistor.
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Answer

(d) Two $P N$-junctions placed back to back cannot work as NPN transistor because in transistor the width and concentration of doping of $P$-semiconductor is less as compared to width doping of $\mathrm{N}$-type semiconductor type.

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