a) What is the power rating of this iron? 720W b) How many joules of energy are produced in 20 minutes? 864,000J c) How much does it cost to run the iron for 20 minutes at $0.01 per kW-hr? $0.0024 1) For a constant resistance, how are potential difference and current related? 2) If the potential difference across a conductor is constant, how is the current dependent on resistance? 3) A nichrome wire with a resistance of 15Ω is connected across the terminals of a 3V flashlight battery. How much current is in the wire? 0.2A 4) A potential difference of 12V produces a current of 0.4A in a piece of wire. What is the resistance of the wire? 30Ω 5) A person notice a mild shock if the current along a path through the thumb and index finger exceeds 80µA. Determine the maximum allowable potential difference without shock across the thumb and index finger for the following: a) Dry skin resistance of 4x10 5 Ω 32V b) Wet skin resistance of 2x10 5 Ω 16V 6) How much power is needed to operate a radio that draws 7A of current when a potential difference of 115V is applied across it? 805W 7) A steam iron draws 6A when connected to a potential difference of 120V. a) What is the power rating of this iron? 720W b) How many joules of energy are produced in 20 minutes? 864,000J c) How much does it cost to run the iron for 20 minutes at $0.01 per kW-hr? $0.0024
This is the end of the preview.
access the rest of the document.