In the circuit shown above, the current through the ammeter is 20 mA and the voltmeter indicates 1.0 V. What is the current through the 40 resistor? A. 7.5mA
B. 10mA
C. 20mA
D. 40mA

20mA

Explanation:

because it is connected in series with the ammeter

v=ir = 3x15 =45 v

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.