Questions

Mutex is a program object that allows multiple program threads to share the same resource, such as file access, but not simultaneously. When a program is started a mutex is created woth a unique name. After this stage, any thread that needs the resource must lock the mutex from other threads while it is using the resource. the mutex is set to unlock when the data is no longer needed or the routine is finished.

Kelvin temperature scale is the temperature scale that is based upon absolute zero.

China has built an 'artificial sun' that reaches 100million °C, 6 times temperature of Sun’s core.

Asterias has bilateral symmetry only at larval stagebut fivefold symmetry (pentamerism, a special type of radial symmetry) as adults.

Nereis do not possess any symmetry elements in their body organisation.

Economics is the study of how society manages its scarce resources i.e, Limited wants & unlimited resources.