How does lightning affect TVs?

Lightning is actually a sudden discharge of high voltage and high current arisiing out of large viltage(potential) differences between charged clouds. These surges, in their path towards the earth, can strike power lines and antennae and pass through the wires to the terminal equipment such as TV. The huge currents and voltages, even though of short life, can damage the electrical components and electronic circuits which are usually designed for low power. The surges are so powerful that they can destroy the equipment even if they are off but connected to the mains/antenna.