They are themselves a binding traffic sign, even without a sign next to them. If there are no priority signs or shark's teeth, traffic from the right goes first.
Correct answer: J10 — level crossing with barriers
Why learners get this wrong: Sign J10 warns of a dangerous crossroads.
Correct answer: Roadworks (J16)
Why learners get this wrong: Sign J16 warns of a level crossing with barriers.
Correct answer: False
Why learners get this wrong: Sign J22 warns of cyclists and moped riders.
Correct answer: You let the car from the right go first; J8 does not regulate priority
False — you confuse the triangle of J8 with the 'give way' sign. J8 is a warning sign and does not oblige you to let all crossing traffic go first. Without priority signs or shark's teeth you give priority only to traffic from the right.
Why learners get this wrong: Sign J8 (dangerous crossroads) itself regulates who has priority at that crossroads.
Correct answer: True
False — you think J17 prescribes a fixed lower speed. A warning sign sets no speed and no obligation; you adjust your speed yourself so that you can stop within the distance you can see and that is clear.
Why learners get this wrong: At sign J17 (road narrowing) you are legally required to a specific, fixed lower speed.