5th August 2024

Explanation - The Bailey Bridge is indeed a type of portable, pre-fabricated bridge designed for

rapid assembly and deployment, particularly useful in military operations. It was developed during World War II to address the need for quick, reliable bridge construction in the field. The Bailey Bridge was first introduced during World War II, not World War I. It became widely used during World War II due to its versatility and the ease with which it could be assembled and disassembled. While the Bailey Bridge is designed to be assembled with minimal tools and equipment, it typically requires the use of cranes or other lifting devices to position and assemble its larger components, particularly for longer spans.

Explanation - Atal Mission for Rejuvenation and Urban Transformation focuses on infrastructure creation that has a direct link to provision of better services to the citizens. It ensures that every household has access to a tap with assured supply of water and a sewerage connection. Unlike JNNURM, AMRUT will not appraise individual projects and appraise only State Annual Action plans. It is a centrally Sponsored Scheme and funds will be allocated to states and Union territories. The states will transfer funds to Urban Local Bodies within 7 days of transfer by central government and no diversion of funds. Central assistance will be to the extent of 50% of project cost for cities and towns with a population of up to 10 lakhs and one-third of the project cost for those with a population of above 10 lakhs. Note: Some of the inadmissible components under AMRUT are Power, Telecom, Health, Education and Wage employment programme and staff component and Purchase of land for projects or project related works, Staff salaries of both the States/ULBs. The list is not exhaustive.

Explanation - Blue stragglers, a class of stars on open or globular clusters that stand out as they are bigger and bluer than the rest of the stars, have intrigued scientists who have for long probed their origin.  bunch of stars born at the same time from the same cloud form a star cluster. As time passes, each star evolves differently depending on its mass. The most massive and bright stars evolve and move off the main sequence creating a bend in their track, known as the turnoff.

Stars above this bend or brighter and hotter stars are not expected in a cluster, as they leave the main sequence to become red giants. But in 1953, Allan Sandage found that some stars seem to be hotter than the turnoff of the parent cluster. Initially, these blue stars still straggling above the turnoff were not part of these clusters. However, later studies confirmed that these stars are indeed cluster members, and they were termed “Blue Stragglers”. The only probable way these stars can still be present in these clusters is if they have somehow acquired extra mass along the way while on the main sequence.

Explanation - A gravity battery is a type of electricity storage device that stores gravitational energy, the energy stored in an object resulting from a change in height due to gravity, also called

potential energy. A gravity battery works by using excess energy (usually from sustainable sources) to raise a mass to generate gravitational potential energy. This is then lowered to convert potential energy into electricity through an electric generator. The most common gravity battery is used in pumped-storage hydroelectricity (PSH), where water is pumped to higher elevations to store energy and released through water turbines to generate electricity. Another form of a gravity battery lowers a mass, such as a block of concrete, to generate electricity. As of 2019, the total world capacity for PSH is 168 GW (gigawatts). The US has 23 GW capacity from PSH, accounting for nearly 2% of the energy supply system and 95% of utility-scale energy storage in the US. Gravity based pumped-storage electricity is currently the largest form of grid energy storage in the world.