% FILENAME = N6.TXT % Resistance % Release version 2, January 2000 %Question: 1 #6.1 The total resistance in a parallel circuit: is always less than the smallest resistance depends upon the voltage drop across each branch could be equal to the resistance of one branch depends upon the applied voltage % ans 1 %Question: 2 #6.2 Two resistors are connected in parallel and are connected across a 40 volt battery. If each resistor is 1000 ohms, the total battery current is: 40 ampere 40 milliampere 80 ampere 80 milliampere % ans 4 %Question: 3 #6.3 The total current in a parallel circuit is equal to the: current in any one of the parallel branches sum of the currents through all the parallel branches applied voltage divided by the value of one of the resistive elements source voltage divided by the sum of the resistive elements % ans 2 %Question: 4 #6.4 One way to operate a 3 volt bulb from a 9 volt supply is to connect it in: series with the supply parallel with the supply series with a resistor parallel with a resistor % ans 3 %Question: 5 #6.5 You can operate this number of identical lamps, each drawing a current of 250 mA, from a 5A supply: 50 30 20 5 % ans 3 %Question: 6 #6.6 Six identical 2-volt bulbs are connected in series. The supply voltage to cause the bulbs to light normally is: 12 V 1.2 V 6 V 2 V % ans 1 %Question: 7 #6.7 This many 12 volt bulbs can be arranged in series to form a string of lights to operate from a 240 volt power supply: 12 x 240 240 + 12 240 - 12 240 / 12 % ans 4 %Question: 8 #6.8 Three 10,000 ohm resistors are connected in series across a 90 volt supply. The voltage drop across one of the resistors is: 30 volt 60 volt 90 volt 15.8 volt % ans 1 %Question: 9 #6.9 Two resistors are connected in parallel. R1 is 75 ohm and R2 is 50 ohm. The total resistance of this parallel circuit is: 10 ohm 70 ohm 30 ohm 40 ohm % ans 3 %Question: 10 #6.10 A dry cell has an open circuit voltage of 1.5 volt. When supplying a large current the voltage drops to 1.2 volt. This is due to the cell's: internal resistance voltage capacity electrolyte becoming dry current capacity % ans 1 %Question: 11 #6.11 A 6 ohm resistor is connected in parallel with a 30 ohm resistor. The total resistance of the combination is: 5 ohm 8 ohm 24 ohm 35 ohm % ans 1 %Question: 12 #6.12 The total resistance of several resistors connected in series is: less than the resistance of any one resistor greater than the resistance of any one resistor equal to the highest resistance present equal to the lowest resistance present % ans 2 %Question: 13 #6.13 Five 10 ohm resistors connected in series give a total resistance of: 1 ohm 5 ohms 10 ohms 50 ohms % ans 4 %Question: 14 #6.14 Resistors of 10, 270, 3900, and 100 ohm are connected in series. The total resistance is: 9 ohm 3900 ohm 4280 ohm 10 ohm % ans 3 %Question: 15 #6.15 This combination of series resistors could replace a single 120 ohm resistor: five 24 ohm six 22 ohm two 62 ohm five 100 ohm % ans 1 %Question: 16 #6.16 If a 2.2 megohm and a 100 kilohm resistor are connected in series, the total resistance is: 2.1 megohm 2.11 megohm 2.21 megohm 2.3 megohm % ans 4 %Question:17 #6.17 If ten resistors of equal value R are wired in parallel, the total resistance is: R 10R 10/R R/10 % ans 4 %Question: 18 #6.18 The total resistance of four 68 ohm resistors wired in parallel is: 12 ohm 17 ohm 34 ohm 272 ohm % ans 2 %Question: 19 #6.19 Resistors of 68 ohm, 47 kilohm, 560 ohm and 10 ohm are connected in parallel. The total resistance is: less than 10 ohm between 68 and 560 ohm between 560 and and 47 kilohm greater than 47 kilohm % ans 1 %Question: 20 #6.20 The following resistor combination can most nearly replace a single 150 ohm resistor: four 47 ohm resistors in parallel five 33 ohm resistors in parallel three 47 ohm resistors in series five 33 ohm resistors in series % ans 3 %Question: 21 #6.21 Two 120 ohm resistors are arranged in parallel to replace a faulty resistor. The faulty resistor had an original value of: 15 ohm 30 ohm 60 ohm 120 ohm % ans 3 %Question: 22 #6.22 Two resistors are in parallel. Resistor A carries twice the current of resistor B which means that: A has half the resistance of B B has half the resistance of A the voltage across A is twice that across B the voltage across B is twice that across A % ans 1 %Question: 23 #6.23 The smallest resistance that can be made with five 1 k ohm resistors is: 50 ohm by arranging them in series 50 ohm by arranging them in parallel 200 ohm by arranging them in series 200 ohm by arranging them in parallel % ans 4 %Question: 24 #6.24 The following combination of 28 ohm resistors has a total resistance of 42 ohm: three resistors in series three resistors in parallel a combination of two resistors in parallel, then placed in series with another resistor a combination of two resistors in parallel, then placed in series with another two in parallel % ans 3 %Question: 25 #6.25 Two 100 ohm resistors connected in parallel are wired in series with a 10 ohm resistor. The total resistance of the combination is: 60 ohms 180 ohms 190 ohms 210 ohms % ans 1 %Question: 26 #6.26 A 5 ohm and a 10 ohm resistor are wired in series and connected to a 15 volt power supply. The current flowing from the power supply is: 0.5 ampere 1 ampere 2 ampere 15 ampere % ans 2 %Question: 27 #6.27 Three 12 ohm resistors are wired in parallel and connected to an 8 volt supply. The total current flow from the supply is: 1 ampere 2 amperes 3 amperes 4.5 amperes % ans 2 %Question: 28 #6.28 Two 33 ohm resistors are connected in series with a power supply. If the current flowing is 100 mA, the voltage across one of the resistors is: 66 volt 33 volt 3.3 volt 1 volt % ans 3 %Question: 29 #6.29 A simple transmitter requires a 50 ohm dummy load. You can fabricate this from: four 300 ohm resistors in parallel five 300 ohm resistors in parallel six 300 ohm resistors in parallel seven 300 ohm resistors in parallel % ans 3 %Question: 30 #6.30 Three 500 ohm resistors are wired in series. Short-circuiting the centre resistor will change the value of the network from: 1500 ohm to 1000 ohm 500 ohm to 1000 ohm 1000 ohm to 500 ohm 1000 ohm to 1500 ohm % ans 1