Voltmeter

Two resistances $500\mathrm{ohm}$ and $1000\mathrm{ohms}$ are connected in series with a battery of $1.5$ volt. The voltage across the $1000\mathrm{ohms}$ resistance is measured using a voltmeter having a resistance of $1000\mathrm{ohm}$. Find the reading in the voltmeter.

A moving coil galvanometer has the following characteristics- Number of turns of coil$=50$, Area of coil$=70{\mathrm{mm}}^2$, Resistance of coil$=30 \Omega$, the flux density of radial field$=0.1\mathrm{T}$, Torsional constant of suspension wire$=7\times {10}^{-8}\mathrm{Nm}/\mathrm{rad}$. Calculate the voltage sensitivity. 

The voltage sensitivity is defined as the deflection per unit current.

What is the SI unit of the voltage sensitivity?

Write the expression of the voltage sensitivity.

A $10\mathrm{V}$ battery with internal resistance $\mathrm{1\hspace{0.17em}}\mathrm{\Omega }$ and a $15\mathrm{V}$ battery with internal resistance $\mathrm{0.6 }\mathrm{\Omega }$ are connected in parallel to a voltmeter (see figure). The reading in the voltmeter will be close to:

Cotyledons are also called-