In which circuit would the bulbs be brighter? 4 0 obj A wire of resistance R is cut into five equal pieces. 1. Find the equivalent resistance between points A and B. The order of the names means nothing. "��NX%^�)�-Ge����kP�%h�4���;'�!��yd�޻�߽�8�����]�������}u&s\zpH+�w��QeC�ȯ�Ș*CM5�z-�/��KZL���T����gT�:0�-w�0��}��OE�@��y�Ӷo�i���³ �P4��u�(1�Q�I�i5�CX�4a��:b��!��Ή|2�e���=��Gm�y��Pa!a�WģN�H��۔���*�W["�v4)|�a�7��f. The equivalent resistance of this circuit (total resistance) can now be calculated. We know that R 3 and R 5 are similarly in series with a resistance of 14 Ω. we can further eliminate answers. Figure 4(B). What is the equivalent resistance between points A and B. be 5.02 mA. Which circuit would have less current in it? 3 0 obj Parallel resistors (part 3) Identifying types of resistor combinations. endstream endobj 2032 0 obj <. An electric bulb is rated as 10 W, 220 V. How many of these bulbs can be connected in parallel across the two wires of a 220 V supply line if the maximum current which can be drawn is 5 A. endobj e cient methods for calculating the equivalent resistance between nodes of highly symmetric networks. %PDF-1.5 In which circuit, if one bulb blows out, all others will stop glowing? Practice: Finding equivalent resistance. ^y`ë²ËÌWddÎ]g0K­U Ân&sÝæbÆô6Ð|õÓêf* ÙóÓáæg`éÒ,¬÷6322p®5(d0 þ5J x��V�n�:��?̒*`�oQ@Q��� E�&7�(��UVl��:�"��֕�ʷ]tC��y����������f This is the currently selected item. Solution . We know the voltage and desired current, so we can calculate the total necessary resistance: Then we can calculate the equivalent resistance of the two resistors that are in parallel (R2 and our unknown): 1 0 obj 4. <>/Font<>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 720 540] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> What is the total resistance? We will be working backwards on this problem, using the current to find the resistance. Four such combinations are connected in series. endobj In fact, it took one extra step to ﬁnd the equivalent resistance. Given: Solution: The original circuit can be redrawn with a single resistor that represents the equivalent 2. How will you connect three resistors of 2 ohm, 3 ohm and 5 ohm respectively so as to obtain a resultant resistance of 2.5 ohm? Choosing two points establishes the resistance path for a passive circuit (no sources). Draw the diagram to show the arrangement. Problem 72. • Find equivalent resistor in new circuit • Solution: Original method: short terminals A and B as shown in the picture. Find the equivalent resistance between points A and B. Find the current I going through A to B. R th can be found by V/I,where V is the voltage we get from last problem. Up Next. Draw the diagram to show the arrangement. Next lesson. Problem 71. The Thévenin equivalent internal resistance R T is the total resistance between A and B after shorting Ten identical bulbs are connected in a parallel circuit to an identical power supply line. Solutions to the problems in Circuit Theory 1. What is the equivalent resistance of this combination in terms of the original resistance R? Four resistances of 16 ohms each are connected in parallel. Solution: Now that the equivalent resistance for R 2 and R 3 has been calculated, the circuit can be redrawn as a series circuit as shown in . 2 0 obj (adsbygoogle = window.adsbygoogle || []).push({}); Ten bulbs are connected in a series circuit to a power supply line. <> And we know that R 1 and R 2 are in parallel, so their equivalent resistance has to be less than 7 Ω (because for resistors in parallel, the equivalent resistance is always less than the branch with the smallest resistance). Solution . %���� R 3 R 4 R 5 R 2 R 1 + – V t i t However, this seems a bit pointless, because ﬁnding equivalent resistance using a test generator was as much work as ﬁnding the source current directly. <> And if the question was asking the equivalent resistance between terminal b and a but not a and b, would it be just the equivalent resistance of 60 and 40 ohms resistances? endobj How will you connect three resistors of 2 ohm, 3 ohm and 5 ohm respectively so as to obtain a resultant resistance of 2.5 ohm? Practice: Identifying types of resistor combinations. <>>> There's absolutely no difference. What possible values of resultant resistance can one get by combining two resistances, one of value 2 ohm and the other 6 ohm? 3. Solving a circuit with series and parallel resistors. Problem 60. stream ����N��p @p!�TJ��*�ؖ���WP �����@¢�,���tn?����� �,����Z +���m�^�P�c8��=�vT T�W���*�ٚL����#�[��� ���4d��\���#����+��2��84.�9HNV�b�JF�� q�n����\�ٶJrk�ڶOpQ��P�'".�GG3�l��: ؄���C�*���\$ey�h6��İ|�ı\�F�[�'"�aCӘr)W'����\��\$���R ���e�-��H������>h���u���FG4B�I̖#S�AZ�Z�J�N7Ew"n��6�����=��:��B���U�C2RlO0o� ��ݕ�W�}�������ߋ ���nIV�iNC��q�H�*�Z��� ���y�P��{��Ov[�*��F�� ² These five pieces of wire are then connected in parallel. What is the total resistance? Then the equivalent resistance is R eq = 10 V / 5.02 mA = 1.99 kΩ. Which circuit would have the highest voltage across each bulb?