When plug prongs are connected to the metal case of an appliance, a part that should always be placed next to the case is a
a. flat metal washer.
b. hexagonal aluminum shoulder.
c. steel nut.
d. mica washer.
The correct answer is (d.) mica washer. When a plug prongs are connected to the metal case of an appliance, a part that should always be placed next to the case is a mica washer. Mica washer are used as a window for any radiation detectors.
