SCR has (A) One PN-junction (B) two PN-junction (C) three PN-junction (D) four PN-junction

Why SCR has Three PN-Junction?

The SCR has three P-N junctions labeled J1, J2, and J3 and three terminals. The cathode terminal of an SCR is connected to the n-type layer, the anode terminal to the p-type material of a PNPN structure, and the gate to the p-type material closest to the cathode.

• A P-N junction is a boundary or an interface between two types of semiconductor material, such as the p-type and the n-type, which is inside a semiconductor.
• The P-N junction is created in a semiconductor by doping. The positive side of the semiconductor contains excess holes, and the negative side contains excess electrons.
• The PNP transistor is formed using three layers of semiconductor material having two P-type and one N-type region.
• The NPN transistor has two n-type semiconductors which sandwich a p-type semiconductor.
• The SCR cathode terminal is connected to the layer of n-type, the anode terminal to the p-type material of a PNPN structure, and the gate to the p-type material is closest to the cathode.

Summary:

SCR has (A) One PN-junction, (B) Two PN-junction, (C) Three PN-junction (D) Four PN-junction

SCR contains three PN junctions. The Silicon Control Rectifier has four semiconductors layers that form PNP or NPN structures, three P-N junctions, and three terminals.