A light goes out when you turn off the wall switch because <u />B. the switch causes a break in the circuit.
Since there is a break in the circuit, electricity cannot come through to the bulb, which is why there is no light anymore.
Answer:
134.77 mm
Explanation:
Wave length of light λ = 599 x 10⁻⁹ m
Slit separation d = 20 x 10⁻⁶ m
Screen distance D = 3 m
Distance of second dark fringe from centre
= 1.5 x λ D / d
Putting the values given above
distance =
= 134.77 x 10⁻³ m
= 134.77 mm.
If you could please give me a already given speed I could estimate it. since there is no speed shown you wouldn't be able to estimate the speed of the moving train.