TalentJR apps
A two-sensor line follower has one light sensor on each side of the line. Its program is a set of rules: if the left sensor sees black, the line has moved left, so turn left; else if the right sensor sees black, turn right; else (both white) the line is between the sensors, so go forward. The robot checks many times a second and wiggles gently along the line. When both sensors see black, the first true rule decides.
✓ You passed this lesson’s test.
Turn towards the line — “the sensor that sees black shows which way the line went”
Use it for: Programming a line follower robot, robotics competitions and if / else practice in coding.
Check: Both white would mean go forward ✓
▶ Watch it animatedWork it out in your head or on paper, type the answer and press Check. Stuck? Press “Show me how”.
Right: 0 · Tried: 0
20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.
🏅 Sign in with Google to earn the ⬛ Line Follower Pro badge when you pass — and a certificate when you finish all 10 lessons of Part 3 · Programming robots. You can still take the test without signing in.
Why does it work? When should you use it? Ask in English, मराठी or हिंदी.
Sign in with Google to ask Free — 20 questions a day.
Prefer a real teacher? TalentJR teachers take live online classes anywhere in India and visit homes in selected cities. Tell us what you need and our team will call you with timings and fees.