Question

A barometer kept in a stationary elevator reads 76 cm. If the elevator starts accelerating up the reading will be

• A. Zero
• B. Equal to 76 cm
• C. More than 76 cm
• D. Less than 76 cm

Answer 1

The correct option is D

Less than 76 cm

$h=\frac{P}{\rho g}\therefore h\propto \frac{1}{g}$. If lift moves upward with some acceleration then effective g increases. So the value of h decreases i.e. reading will be less than 76 cm.