Measurements and Instrumentation - Engineering

Q1:

During testing of an energy meter, the energy recorded by meter was 0.05 kWh and correct energy was found to be 0.09 kWh. The error and correction respectively are

A -0.01 kWh and 0.01 kWh

B 0.01 kWh and -0.01 kWh

C -0.01 kWh and ± 0.01 kWh

D ± 0.01 kWh and 0.01 kWh

ANS:A - -0.01 kWh and 0.01 kWh

Please explain it.