With reference to spectrum usage in 4G networks, what is/are correct? 1. Lower frequency bands provide wider coverage compared to higher frequency bands. 2. Higher frequency bands provide greater data capacity but generally lower coverage.

1. Optical fibres transmit information by converting electrical signals into light pulses. 2. Total internal reflection enables light to propagate through fibre core. 3. Optical fibres are unaffected by physical bending of the cable. Which are correct?

1. Optical fibres are immune to electromagnetic interference. 2. Optical fibres always provide lower latency than wireless communication systems. 3. Optical fibres support high-bandwidth data transmission. Which statements are correct?

1. Optical amplifiers can boost signals without converting them into electrical signals. 2. Dispersion in optical fibres can lead to signal distortion over long distances. 3. Optical fibre communication requires a direct line-of-sight. Which are correct?

1. Micro-OLEDs are typically built on silicon wafers rather than glass substrates. 2. Micro-OLED display emits its own light without requiring a backlight. 3. Micro-OLED displays rely on liquid crystal modulation to produce images. Which are correct?

1. Micro-OLEDs achieve much higher pixel density than conventional OLEDs. 2. Micro-OLEDs are commonly used in compact devices such as AR/VR headsets. 3. Micro-OLEDs use less power than all other display technologies in every scenario. Which are correct?

1. Micro-OLEDs require external illumination to function effectively in low-light conditions. 2. They offer high contrast by turning off individual pixels. 3. They can be integrated with semiconductor circuits on a single chip. Which are correct?

Which are correct for experiments by missions like Axiom-4 on ISS: 1. Microgravity enables experiments hard to replicate on Earth. 2. All experiments focus on space technologies. 3. Studies human physiology for long-duration spaceflight effects.

1. The ISS operates in a microgravity environment suitable for scientific research. 2. The ISS serves as a platform for international cooperation in space exploration. 3. The ISS remains continuously over the same geographical region. Which are correct?

Which of the following experiments is not associated with India’s participation in missions such as Axiom-4 aboard the International Space Station?

1. Lunar orbiters map Moon’s surface and study its composition. 2. Soft landing on Moon requires significant deceleration due to absence of atmosphere. 3. Moon’s gravity is sufficient to cause atmospheric drag during landing. Which are correct?

1. Detection of water ice in polar regions is a key objective of modern missions. 2. Some lunar missions test technologies for sustained human presence on the Moon. 3. Lunar geological studies are irrelevant to Earth’s early history. Which are correct?

1. Communication with lunar missions may require relay satellites for far-side operations. 2. Solar power is unsuitable for lunar missions due to long periods of darkness. 3. Rovers conduct in-situ analysis of lunar soil and rocks. Which are correct?