The following requirements of electric power supply system in surface mines are

Answer: Option E

The requirements of an electric power supply system in surface mines are:

A. Adequate capacity: The power supply system must have sufficient capacity to meet the electrical demands of the mining equipment and facilities.

B. Safe: The power supply system must be designed and maintained to ensure safe operation, with appropriate protections against electrical hazards.

C. Required voltage and frequency: The power supply system must provide the voltage and frequency required by the mining equipment and facilities.

D. Economical: The power supply system must be designed and operated in a cost-effective manner.

Therefore, the answer to this question is Option E, All these.