Final answer:
In Uno, a Skip card is worth 20 points, suggesting high value for action cards. Regarding electric-field lines, a +20 nC charge would result in 20 electric-field lines, illustrating the proportionality between charge magnitude and the number of field lines.
Step-by-step explanation:
According to the original rules for the card game Uno, a Skip card is worth 20 points. The point values in Uno are given to action cards such as Skips, Reverses, and Draws, and they are generally higher than those for numbered cards.
In the case of the Skip card, each is worth 20 points when tallying the score at the end of a game.
Regarding the electric field lines question, electric field lines are a visual tool used to represent the strength and direction of an electric field around a charge.
The number of field lines is usually proportional to the magnitude of the charge. Hence, if a +5 nC charge gives rise to five electric-field lines, a charge that is four times greater, such as +20 nC, would result in four times as many field lines.
Therefore, a +20 nC charge should have 20 electric-field lines.