Three 18th exam questions that cause problems…
1) What is the minimum dimension for a round diameter bonding ring network conductor when considering measures against electromagnetic disturbances?
25mm, 10mm, 8mm or 3mm
It’s 8mm – take a look at 444.5.3 (ii)
2) Which one of the following external influences codes for ambient temperature is conventionally regarded as normal?
AA1, AA2, AA3 or AA4
See page 447 Appendix 5: AA1, AA2, AA3 have a temperature range from -60 deg C to +5 deg C. AA4 is considered normal -5 deg C to +40 deg C as ambient air temperature is considered to be +30 deg C which has a rating / correction factor of 1 (see table 4B1). Note ordinary equipment will also operate safely under conditions -5 deg C to +40 deg C.
3) Which one of the following is the distance that Zone 1 extends above a diving board?
1.0m, 1.5m, 2.0m or 2.5m
Page 245 702.32 (ii) is poorley worded. It means up to a horizontal plane that is 2.5m above where it may be occupied by a person on a diving board. If you have a look on page 250 Fig 702.1 you’ll see what they mean
Hope these help and remember there is a wide selection of online practice exams available with your 18th Edition Online Courses at the-Regs.co.uk