18. 1 ampere is equal to  
a. 1 s/coulomb
b. 1 coulomb/s2
c. 1 coulombĚs 
d.  1 coulomb/s 
19. How has the voltage across a wire changed if the current through the wire is doubled ? 
a. The voltage is reduced by  one half 
b. The voltage  is doubled
c. the voltage  does not change.
d nota
20.What is the effect on the current in a wire if both the voltage across  it and the resistance are reduced by one half? 
a. the current is doubled
b. the current is reduced by one half
c. the current remains the same
21. True or False. 1 coulomb of charge that passes through a resistive wire from the positive terminal  to the negative terminal of a 6-volt battery loses  6 joules of potential energy to heat. 
a. True 
b. False
22. A 5-ohm resistor has a  6 -A current in it. What is the voltage across the resistor? 
a. 30 Volts
b. 5/6  Volts
c. 6/5 Volt