Daily Current Affairs Quiz: January 14, 2026

Answer: C [1 and 2 only]
Explanation:

Statement 1 is correct: A prograde (or posigrade) orbit moves from west to east, the same direction as Earth’s rotation. This allows satellites to take advantage of Earth’s rotational speed.

Statement 2 is correct: A retrograde orbit moves from east to west, i.e., opposite to the direction of Earth’s rotation.

Statement 3 is incorrect: Most Earth-orbiting satellites are launched into prograde orbits, not retrograde ones. Prograde launches save fuel by benefiting from Earth’s rotational velocity. Retrograde orbits actually require more fuel, as they work against Earth’s rotation.

Answer: A [1 and 2 only]
Explanation:

Statement 1 is correct: Semi-cryogenic engines developed by Indian Space Research Organisation use refined kerosene (RP-1) as fuel and liquid oxygen (LOX) as the oxidiser. Fully cryogenic engines, in contrast, use liquid hydrogen (LH₂) with LOX.

Statement 2 is correct: Semi-cryogenic engines are more economical, denser-fuel based, and easier to store and handle at ground level compared to hydrogen-based cryogenic engines, which require extremely low temperatures and complex insulation.

Statement 3 is incorrect: Liquid hydrogen–based cryogenic engines provide a higher specific impulse (Isp) than kerosene-based semi-cryogenic engines. Hence, fully cryogenic engines are better suited for upper stages, not semi-cryogenic ones.

Answer: D [1, 2, and 3]
Explanation:

Statement 1 is correct: A polar orbit has an inclination close to 90°, passing over (or near) both poles. As Earth rotates beneath the satellite, it enables near-global surface coverage over successive orbits.

Statement 2 is correct: Most polar-orbiting satellites operate at altitudes of about 500–1,000 km, which clearly falls within Low Earth Orbit (LEO).

Statement 3 is correct: Polar orbits are ideal for high-resolution Earth observation because their lower altitude allows finer spatial resolution compared to geostationary orbits (~35,786 km), which are too far for detailed imaging.

Answer: B [Only two]
Explanation:

Statement 1 is correct: A pulsar is a rapidly rotating neutron star whose intense radiation beams are emitted from its magnetic poles. When these beams are aligned such that they sweep across Earth, we observe regular pulses of radiation (like a cosmic lighthouse).

Statement 2 is correct: Pulsars are among the rare celestial objects that emit highly polarised radiation, including circularly polarised light, due to their extremely strong magnetic fields and relativistic plasma effects.

Statement 3 is incorrect: Pulsars do not gain angular momentum over time. Instead, they gradually lose rotational energy due to electromagnetic radiation and particle winds, causing them to slow down and eventually cease pulsar activity.

Answer: B [Only two]
Explanation:

Statement 1 is correct: The Cosmic Microwave Background (CMB) is the relic radiation from the early Universe, released about 380,000 years after the Big Bang, when the Universe cooled enough for photons to travel freely through space for the first time.

Statement 2 is correct: CMB radiation does get deflected by dark matter through the phenomenon of gravitational lensing. Massive structures (dominated by dark matter) bend spacetime and hence deflect the path of CMB photons, similar to how a magnifying glass bends light.

Statement 3 is incorrect: This directly contradicts Statement 2. The CMB is affected by gravitational lensing, and this effect is actively used by cosmologists to map the distribution of dark matter in the Universe.