The colour of the bead in the borax bead test is mainly due to the formation of:

How many corners of $SiO_4$ units are shared in the formation of three-dimensional silicates?

Product $(A)$ is

Two simple pendulums whose lengths are $1\,m$ and $121\,cm$ are suspended side by side. Their bobs are pulled together and then released. After how many minimum oscillations of the longer pendulum will the two be in phase again?

The largest number of chloroplasts is found in

An infinitely long straight conductor is bent into the shape as shown below. It carries a current of $I$ ampere and the radius of the circular loop is $R$ metre. Then,the magnitude of magnetic induction at the centre of the circular loop is