SSC CGL 2025 Tier-I · 17 September 2025, Shift 1 · General Awareness · Question 25 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 13 September 2026.

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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.

Consider the following statements about the James Webb Space Telescope (JWST): 1. It observes in the near-infrared and mid-infrared spectrum. 2. It is positioned at the Sun-Earth Lagrange Point L2. 3. It carries a coronagraph for exoplanet detection. Which of the above statements is/are correct?

(a)Only 1 and 2
(b)Only 1 and 3
(c)Only 2 and 3
(d)All 1, 2 and 3

Answer

Why

Correct — D. Statement 1 is true. Webb observes from red visible light through the near- and mid-infrared, about 0.6 to 28.5 micrometres.

Statement 2 is true. It works in a halo orbit around the Sun–Earth L2 point, about 1.5 million km from Earth.

Statement 3 is true. Its NIRCam and MIRI instruments carry coronagraphs that block starlight to image faint planets near bright stars. All three hold: option (d).

Why the others are wrong

(a)
Only 1 and 2 — Drops statement 3. Webb does carry coronagraphs, on NIRCam and MIRI, built to block a star's glare so that nearby planets and disks can be seen.
(b)
Only 1 and 3 — Drops statement 2. Webb works around the Sun–Earth L2 point, about 1.5 million km away, not in low Earth orbit like Hubble.
(c)
Only 2 and 3 — Drops statement 1. Webb is an infrared telescope, covering the near- and mid-infrared, and its sunshield keeps it cold enough to pick up that faint heat.

Concept

The James Webb Space Telescope is a joint NASA, ESA and CSA observatory, launched on 25 December 2021 on an Ariane 5 from Kourou, French Guiana.

It works in the infrared because light from the earliest galaxies is stretched to longer wavelengths, and infrared also passes through dust.

Around L2, the Sun, Earth and Moon stay on one side, so a single sunshield can keep the telescope cold.

Strictly, Webb circles L2 in a halo orbit rather than sitting at the point. The stem's 'positioned at' is the common shorthand, and statement 2 still holds.

Key facts

JWST was launched on 25 December 2021 on an Ariane 5 rocket from Kourou, French Guiana.
It observes from about 0.6 to 28.5 micrometres, red visible light through the mid-infrared.
It operates in a halo orbit around the Sun–Earth L2 point, about 1.5 million km from Earth.
Its NIRCam and MIRI instruments carry coronagraphs for imaging exoplanets and disks close to bright stars.

Study next

Lagrange points L1 to L5 and what each is used forHubble and Webb compared: orbit, wavelengths and mirror sizeCoronagraphs and the direct imaging of exoplanets

Common traps

Rejecting statement 2 because Webb orbits L2 rather than sitting on it: the halo orbit around L2 is what 'positioned at L2' means here.
Mixing up L1 and L2: Aditya-L1 watches the Sun from L1, on the sunward side, while Webb sits beyond Earth at L2, facing away from the Sun.

India's Sun–Earth Lagrange-point mission, Aditya-L1, is asked at 18 Sep 2025, 09:00, GA Q.24 (keyed: a halo orbit around a Lagrangian point).

Related PYQs

No directly related past PYQ was found.

Topic: Scientific Research — all 220 SSC CGL questions on it, every solved shift.