Question

Physical balance is enclosed in glass case.Give reason.

Answer 1

The physical balance is used to measure values correct to millimeters. The physical balance is kept in a glass to ensure that measurements are not interfered with by air currents. 

Answer 2

The physical balance is kept into enclosed glass case because of the fact for its accuracy and precision.  

The physical balance is to measure and quantify the weight of any physical object feasible of measurement inside the physical balance and its beam. That weight is measured inside the glass case so no air resistance may cause any error or hindrance.

Therefore, enclosed in glass case which are air tight initially and measures with accuracy.