Slide 1 / 31 Slide 2 / 31 1 A 60-W light bulb operating on a - PDF document

Slide 1 / 31 Slide 2 / 31 1 A 60-W light bulb operating on a 120-volt household 2 Which of the following is equivalent to the unit of circuit has a resistance closest to electrical resistance? A C/V A 60 Ω B V/A B 120 Ω C A/V C 240 Ω D V/C D 180 Ω E C/J E 360 Ω Slide 3 / 31 Slide 4 / 31 3 A copper wire has a length L and cross-sectional 4 If E is the electric field strength and J is the electric area A. Another copper wire has a length of 2L and current density, what is the ratio of E/J? cross-sectional area 4A. What is the ratio of the A Resistance resistivity of the second wire to the resistivity of the B Resistivity first one? C Voltage A 1/2 D Current B 1/4 E Work C 2/1 D 4/1 E 1/1 Slide 5 / 31 Slide 6 / 31 5 Two tungsten wires with different cross-sectional 6 The following graphs represent the resistivity as a areas and currents are shown on the diagram. function of absolute temperature. Which of the Current I has a cross-sectional are A and runs an graphs shows the resistivity change of a metallic electric current I. Current II has a cross-sectional are wire? 2A and runs an electric current 4I. What is the ration of drift velocity of particles in the second wire to that C A B in the first one? A 2/1 E D B 1/2 C 4/1 D 1/4 E 1/1

Slide 7 / 31 Slide 8 / 31 7 An electric current of 1 A flows through a circuit. The 8 An electric current of 2 A flows through a circuit. The part of the circuit contains a 12 V battery with an part of the circuit contains a 6 V battery with an internal resistance of 2 Ω. What is the voltmeter internal resistance of 0.5 Ω. What is the voltmeter reading? reading? A 4 V A 3 V B 8 V B 4 V C 10 V C 5 V D 12 V D 6 V E 16 V E 7 V Slide 9 / 31 Slide 10 / 31 9 An ammeter with an internal resistance of 3.6x10 -3 Ω 10 A voltmeter with an internal resistance of 20 Ω is is design to measure the maximum current of 0.2 A design to measure the maximum voltage of 2 V (full- (full-scale-deflection). It was predicted that the scale-deflection). It was predicted that the maximum maximum current in the circuit is 2 A. What must the voltage in the circuit is 120 V. What must the shunt shunt resistance be and how it has to be connected resistance be and how it has to be connected to the to the ammeter in order to measure the current in the voltmeter in order to measure the voltage in the given circuit? given circuit? A 3.6×10 -3 Ω in parallel B 3.6×10 -3 in series A 11,800 Ω in series C 4×10 -4 Ω in parallel B 11,800 Ω in parallel D 4×10 -4 Ω in series C 1,180 Ω in series E 1.8×10 -4 Ω in parallel D 1,180 Ω in parallel E 118,000 Ω in series Slide 11 / 31 Slide 12 / 31 11 Five different electric circuits are connected to the 12 Five different electric circuits are connected to the same battery with negligible resistance. Which circuit same battery with negligible resistance. Which circuit has the least current through the battery? produces the greatest power dissipation? B A B A C C E D D E

Slide 13 / 31 Slide 14 / 31 13 The emf of a battery is 6 V. When the battery delivers 14 A wire is connected to a battery of a constant voltage a current of 0.5 A to the external circuit, the potential and negligible internal resistance. By decreasing difference between the terminals of the battery is 5.8 which of the following we can increase the power V. The internal resistance of the battery is dissipated in the wire? A 0.4 Ω A L only B 4 Ω B d only C 0.6 Ω C L and ρ only D 6 Ω D d and ρ only E 2 Ω E ρ only Slide 15 / 31 Slide 16 / 31 15 Two resistors with resistance 3 Ω and 2 Ω 16 Two resistors with resistance of 30 Ω and 60 Ω respectively are connected in series with a 12 V respectively are connected in parallel with a 6 V battery. The current in the circuit is 2 A. What is the battery. The current in the circuit is 0.25 A. What is internal resistance? the internal resistance? A 1 Ω A 1 Ω B 2 Ω B 2 Ω C 3 Ω C 3 Ω D 0.5 Ω D 4 Ω E 0.2 Ω E 5 Ω Slide 17 / 31 Slide 18 / 31 17 Which of the following graphs represents the current 18 A rheostat is connected across a battery with a as a function of resistance? constant voltage. Which of the following graphs represents the power P dissipated by the rheostat as a function of its resistance R? B A B A C C E D D E

Slide 19 / 31 Slide 20 / 31 19 Three identical resistors are connected to each other 20 A wire of resistance R dissipates power P when a in four different combinations. Which of the given current I passes through it. The wire is replaced by circuits has the greatest resistance? another wire with resistance 3R. The power dissipated by the new wire when the same current passes through it is I II IV III A Only I B Only II A P/9 C Only III B P/3 D Only IV C P E II and IV D 3P E 6P Slide 21 / 31 Slide 22 / 31 21 The circuit in the diagram above contains three iden- tical light bulbs connected as shown. Initially, a 22 What is the current in the circuit above? switch connected to light bulb I is closed. Which of the following is correct about brightness of light A 4 A bulb II and III is correct when the switch is open? B 2 A Bulb II Bulb III C 1 A A Gets brighter Gets dimmer D 0.5 A B Gets dimmer Gets brighter C Gets brighter Gets brighter E 0.25 A D Gets dimmer Gets dimmer E Goes out Gets brighter Slide 23 / 31 Slide 24 / 31 23 What the potential difference across the 2 Ω resistor 24 The power dissipated in 6 Ω resistor in the circuit in the circuit above? above is close to A 1 V B 2 V A 10.7 W B 5.3 W C 4 V C 24.5 W D 6 V D 37.2 W E 18 V E 43.4 W

Slide 25 / 31 Slide 26 / 31 25 Which of the following is true about the current 26 Which of the following is true about the current through resistor R and charge in the capacitor, through resistor R and charge in the capacitor, when immediately after the switch is closed? the switch is closed for a long time? Current I Charge Q Current I Charge Q A Zero Maximum A Zero Maximum B Maximum Zero B Maximum Zero C Zero Zero C Zero Zero D Maximum Maximum D Maximum Maximum E Stays unchanged Stays unchanged E Stays unchanged Stays Unchanged Slide 27 / 31 Slide 28 / 31 27 A circuit is connected to a 9 V battery with a net 28 A resistor R = 1x10 6 Ω, a capacitor C = 1 nF are resistance of 40.5 Ω. How much energy is dissipated connected in series with a battery V and switch S. by the circuit in time interval of 1 min? What is the time constant of the circuit? A 120 J A 10 -6 s B 240 J B 10 -3 s C 360 J C 10 -9 s D 60 J D 10 6 s E 30 J E 10 3 s Slide 29 / 31 Slide 30 / 31 29 In order to measure the current and voltage through 30 A battery with internal resistance R and an a circuit how must an ammeter and voltmeter be electromotive force ε supplies a current I to a light connected to a circuit? bulb of resistance r. The power dissipated by the circuit is Ammeter Voltmeter A in parallel in series A ε 2 /(R+r) B in parallel in parallel B (ε-IR) 2 /R C in series in series C (ε-IR) 2 /(R+r) D in series in parallel D ε 2 /R E none from the above none from the above E (ε+IR) 2 /(R+r)

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