Question 705064

A piezoresistive pressure sensor utilizes change in electrical resistance ($\Delta R$) with change in pressure ($\Delta P$) as $\Delta R = -R_0 \log_{10} (\frac{\Delta P}{P_0})$, where $R_0 = 500 \Omega$ and $P_0 = 1000 \text{mbar}$. A current of $2 \mu A$ is passed through the sensor and the resultant voltage drop is measured using an analog-to-digital (ADC) converter having a range 0 to 1 V. If a pressure change of 1 mbar is to be measured, amongst the given options, the minimum number of bits needed for the ADC is