Discussion

Match the detector for a scanning electron microscope (SEM) in Column I with the resulting output in Column II.

SE: Secondary electrons; BSE: Backscattered electrons; EDS: Energy Dispersive Spectroscopy; EBSD: Electron Backscatter Diffraction

Column I	Column II
(P) SE Detector	(1) Elemental composition analysis
(Q) BSE Detector	(2) Kikuchi lines
(R) EDS Detector	(3) Topographic image
(S) EBSD Detector	(4) Compositional contrast image

Answer: D

The match is P-3; Q-4; R-1; S-2.

Secondary electrons are low-energy electrons escaping from a thin surface layer, so their yield depends on surface tilt: the SE detector gives a topographic image.
The backscattered yield rises with atomic number, so the BSE detector gives a compositional contrast image.
EDS sorts the characteristic X-rays by energy: elemental composition analysis.
EBSD records the diffraction of backscattered electrons as Kikuchi lines, used to find crystal orientation.

The other options misassign at least one detector; for example P-4 gives secondary electrons the atomic-number contrast that belongs to BSE.

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