Answers of the definition of voltage(Duplicates possible).
| Criteria of answers | Number of answers(%) | |||
| Students | Pre-service teachers (11) | |||
| Elementary Middle school(12) | High school (22) | Total (34) | ||
| The force or pressure of electricity | 4(33.3%) | 9(40.9%) | 13(38.2%) | 1(9.1%) |
| The strength of electricity or magnitude of electrical energy | 5(41.7%) | 9(40.9%) | 14(41.1%) | 1(9.1%) |
| The source of an electric current* | 0(0.00%) | 2(9.1%) | 2(5.9%) | 2(18.2%) |
| The difference in electric potential* | 2(16.7%) | 1(4.5%) | 3(8.8%) | 7(63.6%) |
| Others | 3(25.0%) | 8(36.4%) | 11(32.4%) | 1(9.1%) |
*: Scientific answers