Why is a generator armature harder to rotate when it is connected to a circuit and supplying electric current?

In physics the desire of an object to keep doing what it is doing is termed?

Photoelectrons with a maximum speed of 6.50 x 107 m/s are ejected from a surface in the presence of light with a frequency of 6.75 x 1014hz. if the mass of an electron is 9.10 x 10-31 kg, calculate in joules the maximum kinetic energy of a single electron. 3.84 x 10-15 j 1.92 x 10-15 j 5.92 x 10-23 j 3.07 x 10-16 j

If the textbook weighs 19.6 newtons on venus,what is the strength of gravity on venus?