19) why will a lamp with a 100-ohm filament burn brighter than a lamp with a 300-ohm filament?

Brightness of the bulb is dependent on the power dissipated across the bulb

so the formula to find the power across any resistor is given by

so here since all circuit elements are connected in parallel in the given circuit

so voltage across all elements will remain the same

so here we can say that power across element is inversely depends on the value of the resistance

so here if we compare the power across 100 ohm and 300 ohm the brightness of 100 ohm will be more.

So the power across 100 ohm will be more as we compare it with the power across 300 ohm

0.93xc=0.93x3x10^8m/s

2.54cm is 1 inch

360seconds i 1 hr