Answer:
Lesser Force is required to open the nut
Explanation:
Since we are talking about rotation, lets use moments to explain this. Moments can be calculated using the formula: M = F × d where F is the amount of force applied and d is the perpendicular distance from pivot to line of action of a force. It takes a certain moment to unscrew the nut. Let say it takes 10Nm to unscrew and our spanner in 1m. Hence,
10Nm = F × 1m
F = 10 N
By using a 1m spanner, we require 10N of force to open the nut. Now, lets use a 2m spanner.
10Nm = F × 2m
F = 5N
As you can see, by using a longer 2m spanner, we require lesser force to open the nut, making it easier for us to open the nut using a longer spanner.
[There is no 1m or 2m spanner in real life. I just created dummy values for explanation :) ]