2330-205 practice paper

[L Plate]

1. A circuit wired in 1.5 mm2 thermoplastic (pvc) twin with cpc cable is protected by a 16 A device and is used to supply a 230 V 3 kW water heater. If the cable has a rated voltage drop of 29 mV/A/m and the circuit is 24 m long, the actual voltage drop will be

a 2.08V

b 9.07V

c 11.14V

d 69V.

2. A 50 mm x 50 mm steel trunking has a tabulated space factor of 1037. If the tabulated factor for PVC cable having a cross sectional area of 6 mm2 is 21.2, the maximum number of these cables that can be installed into the trunking is

a 47

b 48

c 49

d 50

3. And is there any simple way on how to calculate ratio scale please < I am always stuck on calculating this , e;g 1:10 / 1:30 or let say having a scale of 1:50, a wall 10 m long would be drawn to a length of

a 10 mm / cm /

thanks again

Have a nice day all

 

[m4tty]

Number 1: I would say answer is b. 29mv/a/m is 29 x 13.04a x 24 metres devided by 1000 is 9.07v. The 13.04 is from 3000w / 230v . Hth

If you used 16a instead of 13.04a then it would come out as answer c but that wouldn't be the ACTUAL voltage drop, so I would go with b.

I'm so glad I've passed all my level 2 and 3 and got distinctions as without alot of revision I don't think I'd do so well again lol

 

[m4tty]

Number 2 : 1037 / 21.2 = 48.91 therefore answer is 48 cables