which may the reasons for non working tester
Answers
Answer:
The tester (in India) usually works at voltages above 150 or 180 V. the usual supply in wall sockets is about 230V. At such a high voltage a very very tiny, perhaps micro amps of current flows through our body to earth and that is enough to light up a small neon bulb. The AC supply has somewhat similar magnitude with reference to earth also.
If you connect tester to a 12V or 24V DC supply (one end of feet or body part on ground) , the current would be even smaller than micro amps - may be nano amps and that is not sufficient to create a glow in neon. This is assuming that negative terminal of DC power supply is earthed. If it is not then even that nano amps current will also not flow.
Explanation:
Undefined Quality Standards. Software products tend to comply with quality requirements when the standards are clearly defined. ...
Test Environment Duplication. ...
Lack of Communication. ...
Unstable Environment. ...
Insufficient Requirements Gathering.