Earthquakes at two places A and B were measured by a seismograph which recorded the magnitude as 2 and 4. The magnitude of tremors and the destructive energy at A and B can be compared as
A Tremors at B are two times those at place A
B Tremors at B are four times those at place A
C Tremors at B are 100 times those at place A
D Tremors at B are 1000 times those at place A.
pls tell how to calculate