can we get white light by mixing blue and yellow lights?

Answer 1

yes,absolutely

Answer 2

No >The impression of white light can be created by mixing, via a process called additive mixing, appropriate intensities of the primary color spectrum: red, green and blue, but it must be noted that the illumination provided by this technique has significant differences from that produced by incandescence.

Answer 3

Yes you can. The additive primaries are red, blue and green. The combination of all three is white. The subtractive primaries are magenta, cyan and yellow, and you get these by subtracting one of the additive primaries from white light:

magenta = white - green
cyan = white - red
yellow = white - blue

Therefore if you add yellow to blue, you get white.