Planet.3.astar is 10 light years away from the earth. suppose it brightens up suddenly today, after how long can we see this change?

Wavelength, frequency, and energy are related. what happens to a wave as it’s wavelength gets shorter?

Electromagnetic induction. a coil of wire contains n turns and has an electrical resistance r. the radius of each turn is a. initially, inside the coil there exists a uniform magnetic field of magnitude b0 parallel to the axis of the coil. the magnetic field is then reduced slowly. the current induced in the coil is i. how long does it take for the magnitude of the uniform field to drop to zero?

The built in flash in a compact camera is usally capable of giving correct exsposure for distance up to how many meters?