How can a star be extremely hot like Alpha Canis Majoris (4 times hotter than our sun) but give off so little light (only 2% of our sun's light)?

How does a circuit breaker protect a refrigerator? a. when the current is too high, a metal strip in the fuse melts and opens the circuit. b. when the resistance is too high , a re-settable which opens a circuit c. when the current is too high , a re-settable switch opens the circuit d. when the resistance is too high a metal strip in the fuse melts and opens the circuit