SSC CGL 2025 Tier-I · 15 September 2025, Shift 3 · General Awareness · Question 24 of 100

We transcribed this text from the pictures on a candidate's response sheet for this shift; the answer is the key SSC colour-marked on that sheet. Solution last reviewed 11 September 2026.

Where this paper and its answers come from

SSC does not publish CGL question papers or a public answer key. From 2025 the candidate response sheet prints every question and option as a picture, so the text here is transcribed from those pictures for this shift and checked against them independently; where the layout carries meaning, the picture is shown as well. Each answer is the key SSC colour-marked on that sheet. SSC released a tentative key for challenge and later its final one, both only to candidates behind a login, and the sheet does not say which of the two it carries. The solutions are written by UnlockIAS.

Which payload monitors solar wind at L1?

(a)ASPEX
(b)SUIT
(c)SoLEXS
(d)HEL1OS

Answer

Why

Correct — A. Aditya-L1 carries seven payloads: four view the Sun remotely, and three study particles and fields in situ at the L1 point.

ASPEX, the Aditya Solar wind Particle Experiment, is one of the in-situ three. ISRO lists it as a solar wind and particle analyser for protons and heavier ions, so it monitors the solar wind: option (a).

Why the others are wrong

(b)
SUIT — SUIT, the Solar Ultraviolet Imaging Telescope, is a remote-sensing payload. It images the photosphere and chromosphere in near ultraviolet rather than sampling wind at L1.
(c)
SoLEXS — SoLEXS is a soft X-ray spectrometer that observes the Sun as a star. It reads the Sun's light, not the particles of the solar wind.
(d)
HEL1OS — HEL1OS is a hard X-ray spectrometer, another remote-sensing payload, which has recorded solar flares in high-energy X-rays. It does not sample the solar wind.

Concept

Aditya-L1 is India's first space-based mission to study the Sun. It sits in a halo orbit around the Sun-Earth L1 point, about 1.5 million km from Earth, where it views the Sun without eclipses.

Its remote-sensing payloads are VELC, SUIT, SoLEXS and HEL1OS. Its in-situ payloads are ASPEX, PAPA and a magnetometer.

PAPA, the Plasma Analyser Package for Aditya, also analyses the solar wind, for electrons and heavier ions. It is not among the options, which leaves ASPEX.

Key facts

Aditya-L1 launched on PSLV-C57 on 2 September 2023 and entered its halo orbit around L1 on 6 January 2024.
ASPEX is an in-situ solar wind and particle analyser for protons and heavier ions.
SUIT is a remote-sensing imager of the photosphere and chromosphere in near ultraviolet.
SoLEXS and HEL1OS are soft and hard X-ray spectrometers observing the Sun as a star.

Study next

VELC, the Visible Emission Line Coronagraph, and the study of the coronaLagrange points and why L1 gives an uninterrupted view of the SunSolar wind, coronal mass ejections and space weather

Common traps

Picking SUIT because "Solar" is in its name: it is a telescope that images the Sun, not a particle detector.
Assuming every payload at L1 measures L1 itself: only ASPEX, PAPA and the magnetometer sample their surroundings.

Here one payload is matched to its job. Aditya-L1's main target is asked at 14 Sep 2025, 12:30, GA Q.12 (keyed Corona).

Related PYQs

No directly related past PYQ was found.

Topic: Scientific Research — all 178 SSC CGL questions on it, every solved shift.