CT 29 1a Consider the following four situations i An ion charge Q moves to the right ii A neutral hydrogen atom proton e and light electron e moves right iii A beam of electrons in a TV shoots right iv In an ionic solution massive positive ions flow right light negative electrons flow with equal speed to the left In which of these is the net current ZERO A All of the above B ii only C iv only D ii and iv only E None of these CT 29 1b Consider the following four situations i An ion charge Q moves to the right ii A neutral hydrogen atom proton e and light electron e moves right iii A beam of electrons in a TV shoots right iv In an ionic solution massive positive ions flow right light negative electrons flow with equal speed to the left In which is the net current to the RIGHT A i only B iii only C iv only D i and iv only E None of these CT 29 2a A copper cylinder is machined to have the following shape The ends are connected to a battery so that a current flows through the copper A B C Which region has the greatest current density J A B C or D All three are the same E not enough info CT 29 2b A copper cylinder is machined to have the following shape The ends are connected to a battery so that a current flows through the copper A B C Which region has the greatest magnitude of current i A B C or D All three are the same E not enough info CT 29 2c A copper cylinder is machined to have the following shape The ends are connected to a battery so that a current flows through the copper A B C Which region has the greatest conductivity A B C or D All three are the same E not enough info CT 29 2d A copper cylinder is machined to have the following shape The ends are connected to a battery so that a current flows through the copper A B C Which region has the greatest magnitude electric field E A B C or D All three are the same E not enough info CT 29 2e So far we have concluded J is greatest in region B Using J E and J I A A B C The ratio of diameters is A B C 3 1 5 How much larger magnitude is the drift velocity vd in region B compared to C A same B 25x greater C 5x greater D slower in region B E none of these Hint J nq vd CT 29 3 Two cylindrical resistors are made of the same material same resistivity 1 Resistor 2 is twice as long and has twice the diameter of resistor What is the ratio R2 R1 A 2 C 1 2 E 1 B 4 D 1 4 2 CT 29 7 Your slightly crazed physics professor wants to grab both poles of a regular 12 V car battery What happens A STOP Don t let her do it certain death B Warning This is going to hurt a little C Let her go for it She won t notice a thing 12 V CT 29 6b Household appliances all have V 120 V What is the approximate resistance of the filament at operating temperature of a 100W lightbulb A R 100 Ohms B R 144 Ohms C R 1250 Ohms D None of the Above CT 29 14 A household 40W light bulb and a 60W light bulb each has a filament with a certain resistance when the bulb is on and hot How do the resistances of the filaments compare A R 40W R 60W B R 40W R 60W C R 40W R 60W D Need more info CT 29 14b These two bulbs are now put in series which is not a normal thing to do Which bulb glows brighter A both have same brightness B 40W is brighter 40 W C 60W is brighter D Not enough info V 60 W Hints More power brighter When light bulbs are in series they have the same current Light bulbs are intended to operate at 120V CT 29 13e We start with the left circuit with bulb A If we add a second bulb B as shown on the right what happens to bulb A A Bulb A is equally bright B Bulb A is dimmer than before C Bulb A is brighter than before A A V B V CT 29 9 Two identical resistors are wired in series one behind the other R R I If there is an electric current I entering the combination the current exiting the second resistor is A Equal to B Half C Smaller than but not necessarily half the current in the first resistor CT 29 8 Current flows through a light bulb Suppose a wire is connected across the bulb as shown When this wire is connected A All the current continues to flow through the bulb B Half the current flows through the bulb half through the wire C All the current flows through the wire CT 29 19 A 1 resistor is placed in parallel with a 10 000 resistor as shown The total equivalent resistance of these two resistors in parallel is A a little less than 1 B a little more than 1 C about 5000 D a little less than 10 000 E a little more than 10 000 CT 29 12c R1 10 R2 5 What s the current through the 10 resistor A 1 A B 2 A C 3A D 5 A E 6A CT 29 12d R1 10 R2 5 What s the voltage drop across the 10 resistor i e V AB A 30 V B 20 V C 15 V D 10 V E 0 V CT 29 18 What is the voltage at points A B C and D A VA VB 6 VC VD 0 B VA VB 12 VC VD 6 C VA VB 12 VC VD 0 D 12 VB VA VC VD 0 ground CT 29 12q R1 6 R2 12 Compare the current flowing past points A and B A IA IB B IA 2 IB C IA 0 5 IB D IA 3 IB E IA 1 3 IB CT 29 10 Current is flowing through wires which are part of a circuit as shown What is the current in the wire at the bottom right 1A A 1 A to the left B 1 A to the right C 3 A to the left D 3 A to the right E none of these not sure 2A I CT 29 27 The current directions have been guessed as shown Which is the correct current equation for this circuit I1 R1 V1 R2 V2 I2 Loop 1 R3 I3 A I2 I1 I3 B I1 I2 I3 C I3 I1 I2 CT 29 27b What is the correct voltage equation for loop 1 …
View Full Document
Unlocking...