Physics Help Forum Current electricity

 Electricity and Magnetism Electricity and Magnetism Physics Help Forum

 May 6th 2010, 07:01 AM #1 Junior Member   Join Date: Nov 2008 Posts: 5 Current electricity Referring to the attached diagram, the reading of the voltmeter is 8V. The objective is to find the resistance of resistor R. I assumed that the p.d. across the 160 ohm resistor = 8V, and used the method of potential dividers and found R to be 50 ohms. However, the answer given was R= 38 ohms. Have I overlooked something here? Sorry if it seems like a nooby question. Attached Thumbnails
 May 6th 2010, 12:34 PM #2 Senior Member   Join Date: Mar 2010 Location: Lithuania Posts: 105 If two conditions are fulfiled: 1) The internal resistance of an ideal voltage source is zero 2) The internal resistance of the voltmeter is infinite I get also 50 ohm.
 May 13th 2010, 02:12 AM #3 Banned   Join Date: May 2010 Posts: 6 The flow of water in a river constitutes a current of water, flow of charge, i.e. charges in motion constitute an electric current. - The charged particles whose flow in a definite direction constitutes the electric current are called current carriers.e.g. electrons in conductors,ions in electrolytes,electrons and holes in semiconductors. The essential requirement for maintaining a steady current is a source of e.m.f. e.m.f. is associated with an arrangement or mechanism which can supply energy or does work to move the electric charge from lower potential energy to higher potential energy.

 Tags current, electricity

 Thread Tools Display Modes Linear Mode

 Similar Physics Forum Discussions Thread Thread Starter Forum Replies Last Post engchunh Electricity and Magnetism 4 Dec 18th 2013 06:18 AM dslt Advanced Electricity and Magnetism 0 Oct 18th 2011 08:21 AM coolnufc Advanced Electricity and Magnetism 2 Feb 25th 2009 10:50 AM omkar13 Electricity and Magnetism 1 Feb 13th 2009 07:49 PM