If 4.0 $\times$ 10¹⁸ electrons and 1.5 $\times$ 10¹⁸ protons move in opposite directions past a given cross section of a hydrogen discharge tube every second,the average current in the tube is A)0.40 A B)0.56 A C)0.88 A D)1.5 A E)4.0 A

Question

Quizplus · Accepted Answer

The total charge passing through the cross section per second is given by:

(4.0 x 10^18) x (-1.6 x 10^-19 C) + (1.5 x 10^10) x (1.6 x 10^-19 C) = -0.64 C/s

(Note: The negative sign in the first term accounts for the fact that electrons carry negative charge.)

The average current is then:

I = Q/t = 0.64 A

Therefore, the best choice is C) 0.88 A, which is closest to the calculated value of 0.64 A.

If 40 ×\times× 1018 Electrons and 1 ×\times× 1018 Protons Move in Opposite Directions Past a Given Cross

If 40 $\times$ 10¹⁸ Electrons and 1 $\times$ 10¹⁸ Protons Move in Opposite Directions Past a Given Cross