Consider the following statements: 1. Light of longer wavelength is scattered much more than the light of shorter wavelength. 2. The speed of visible light in water is 0.95 times and speed in vacuum. 3. Radio waves are produced by rapidly oscillating electrical currents. 4. To detect the over speeding vehicles, police use the Doppler effect of reflected short radio waves Which of these statements are correct?

Statement 1 is incorrect because according to Rayleigh scattering, light of shorter wavelengths such as blue and violet is scattered much more than light of longer wavelengths like red. Statement 2 is incorrect because the refractive index of water is approximately 1.33, which means the speed of light in water is roughly 0.75 times its speed in a vacuum, not 0.95. Statement 3 is correct because radio waves are electromagnetic waves generated by the acceleration of electrons in an antenna, which is caused by oscillating electric currents. Statement 4 is correct because police radar guns emit radio waves that reflect off a moving vehicle. The frequency of the reflected wave changes based on the vehicle speed due to the Doppler effect, allowing the device to calculate the speed. Since statements 3 and 4 are true, the correct option is D.