19. What is the most likely outcome of increasing the number of slits per unit distance on a diffraction grating? a. lines become narrower b. distance between lines increases c. lines become thicker d. distance between lines decreases

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.

wavelength divides in half and speed stays the same.