What does "y" represent in the given chart?

The magnetic needle of a tangent galvanometer is deflected at an angle $30^{\circ}$ due to a magnet. The horizontal component of the Earth's magnetic field is $0.34 \times 10^{-4} \text{ T}$,which is along the plane of the coil. The magnetic field due to the magnet is:

One of the constituents of the pancreatic juice while poured into the duodenum in humans is

If the electron of a hydrogen atom is present in the first orbit,the total energy of the electron is

Which of the following terms is used to refer to the number of varieties of plants and animals on Earth?

The ratio of the total energy of the $2^{\text{nd}}$ orbit electron for the hydrogen atom $1H^1$ to that of the helium ion $(He^{+})$ $2He^4$ is: