Acircuit is supplied with 60 vdc and contains two series resistors with values of 100 and 400 . what is the total current in the circuit?
a. 2 a
b. 0.82 a
c. 1.2 a
d. 0.12 a
what circuit quantity is measured by connecting a meter's test leads in series with an energized component?
a. resistance
b. power
c. voltage
d. current

When resistors are connected in series, they act like
a single resistor whose resistance is their sum. 

100 ohms and 400 ohms, connected in series, look like
a single resistor of 500 ohms.

           Current = (voltage) / (resistance)

                        = (60 volts) / (500 ohms) = 0.12 A.


Current is measured by connecting a meter in series
with an energized component.  In other words, a break
is made in the circuit, the meter is connected in the break,
and the current to be measured literally flows through the meter.

Not sure but i think it's b.

Blue light reflected from the ball enters human eyes.