$A$ beaker contains $200\, g$ of water. The heat capacity of the beaker is equal to that of $20\, g$ of water. The initial temperature of water in the beaker is $20^\circ C$. If $440\, g$ of hot water at $92^\circ C$ is poured into it,the final temperature (neglecting radiation loss) will be nearest to $^\circ C$.

The idea of secondary wavelets for the propagation of a wave was first given by

A small block of mass $m$ slides down from the top of a frictionless inclined surface, while the inclined plane is moving towards left with constant acceleration $a_{0}$. The angle between the inclined plane and ground is $ heta$ and its base length is $L$. Assuming that initially the small block is at the top of the inclined plane, the time it takes to reach the lowest point of the inclined plane is . . . . . . . .

An object takes $n$ times as much time to slide down a $45^{\circ}$ rough inclined plane as it takes to slide down a perfectly smooth inclined plane of the same inclination. The coefficient of kinetic friction between the object and the rough incline is given by:

The pelvic girdle of birds is attached to a complex structure formed by the fusion of the last thoracic,all lumbar,and the first five caudal vertebrae. This structure is called:

Which one of the following correctly represents the variation of electronegativity $(EN)$ with atomic number $(Z)$ of group $13$ elements?