Can one use 20W fluorescent tube lamps as a substitute to 40W lamps?
Yes they will work if they fit the fixture.... They will only draw the 20 watts they need to operate, so No, you will not blow the 20W lamps.... Ensure however that the lamps you will be using are rated for 220 volt operation... I am guessing you are...
If two lamps, L1 and L2, were connected in parallel and a solder bridge shorted L1, then:?
Both lamps would be off. Since the lamps are in parallel they share the connections, so shorting L1 also shorts L2. Then there is no way for either one to get electricity and that means both are off.
New flourescent tubes flickering?
Sounds like you need a new ballast in your fixture and it's very possible that you got a bad lamp. Try putting one of the yellow lamps with one of the daylight lamps and then switch the daylight lamps to see if one of them doesn't work. More than lik...