Context: A railway electrification system supplies electric power to railway trains and trams without an on-board prime mover or local fuel supply. Electrification has many advantages but requires significant capital expenditure. Selection of an electrification system is based on economics of energy supply, maintenance, and capital cost compared to the revenue obtained for freight and passenger traffic. Different systems are used for urban and intercity areas; some electric locomotives can switch to different supply voltages to allow flexibility in operation.

Question: What is of the factors the capital cost of electrification system depends on?
Answer: maintenance

Question: How do some locomotives function in order to be more flexible in operation?
Answer: can switch to different supply voltages

Question: What is the main disadvantage of railway electrification?
Answer: significant capital expenditure

Question: What are two types of revenue obtained through railway transportation?
Answer: freight and passenger traffic

Question: What system supplies nuclear power to railway trains?
Answer: Unanswerable

Question: What requires insignificant capital expenditure?
Answer: Unanswerable

Question: The same systems are used for both urban and intercity what?
Answer: Unanswerable

Question: All electric locomotives can switch to different supply voltages to allow for what?
Answer: Unanswerable

Question: A railway electrification system supplies power to trains and trams with an on-board what?
Answer: Unanswerable