What is induced emf? Write Faraday’s law of electromagnetic induction. Express it mathematically. A conducting rod of length ‘l’ with one end pivoted, is rotated with a uniform angular speed ‘ω’ in a vertical plane, normal to a uniform magnetic field ‘B’. Deduce an expression for the emf induced in this rod. In India, domestic power supply is at 220 V, 50Hz, while in USA it is 110 V, 50 Hz. Give one advantage and one disadvantage of 220 V supply over 110 V supply.