Circuits Concept Tests.CRKT-1Vote TRUE(A) if both statements below are always true. Otherwise, vote FALSE(B). BOTH TRUE (A) or ONE OR BOTH FALSE (B) ?- For resistors in series, the current through each resistor isthe same.- For resistors in parallel, the voltage across each resistor is the same.CRKT-2A 1- resistor is placed in parallel with a 10,000 - resistor as shown.The total, equivalent resistance of these two resistor in parallel is closest to...A) a little less than 1- B) a little more than 1-.C) 5000 - D) a little less than 10000-E) a little more than 10000-I1 Ω 10,000 ΩCRKT-3 The circuit below consists of a battery attached to two resistors in series. Resistor R1 is variable. When R1 is decreased, the voltage V2 across R2 ...A) increases B) decreases C) stays the same.R2R1V1I1V2I2VCRKT-4Two resistors R1 and R2 are hooked to a battery in parallel. R1 is twice as large as R2. How does the current IB from the battery compare to the current I1 though R1? (Hint: IB = I1+ I2.)A) IB = I1B) IB=2I1C) IB=3I1D) IB=4I1E) None of these.R1I1VR2I2= 2 R2IBCRKT-5The four light bulbs shown are identical. Which circuit puts out more light? (Hint: more power = more light). (A) (B)(C) They both put out the same amount of light.V = 12VV = 12VCRKT-6In the circuit below, what happens to the brightness of bulb 1, when bulb 2 burns out? (When a bulb burns out, its resistance becomes infinite.)A) Bulb 1 gets brighterB) Bulb 1 gets dimmer.C) Its brightness remains the same.(Hint: What happens to the current from the battery when bulb 2 burns out.)V = 12V132V = 12VBCACRKT-7The three light bulbs A, B, and C are identical. How does the brightness of bulbs B and C together compare with the brightness of bulb A?A) Total power in B+C =power in A.B) Total power in B+C > power in A.C) Total power in B+C < power in A.CRKT-8 Two glowing light bulbs are in a battery-operated circuit. Light bulb A has greater resistance than light bulb B. Which light bulb is brighter?A B C) Depends on the circuit.V R3R1R2(B)(C)(A)(D)CRKT-9If you wanted to measure thecurrent through the battery,where in the circuit would youplace an ammeter?(A), (B), (C), (D), or (E) None of these will work.If you wanted to measure the current through resistor R2, where would you place and ammeter?(A), (B), (C), (D), or (E) None of these will work.CRKT-10A circuit with two batteries is shown below. The directionsof the currents have been chosen (guessed) as shown. Which is the correct current equation for this circuit?A) I2 = I1 + I3 B) I1 = I2 + I3C) I3 = I1 + I2D) None of these.R1V1V2R3R2I2I1Loop 1I3CRKT-11 Which is the correct equation for Loop 1?A) –V2 + I1R1 – I2R2 = 0 B) V2 + I1R1 – I2R2 = 0C) –V2 + I1R1 + I2R2 = 0 D) V2 + I1R1 + I2R2 = 0E) None of these.R1V1V2R3R2I2I1Loop 1I3CRKT-12 What happens to the (identical) bulbs when the switch is closed?A) A glows, B changes B) A glows, B stays sameC) A stays same, B changesD) A stays same, B stays same12V12VswitchABCRKT-13 A flashlight requires 2 AA (1.5V) batteries, and is arranged as shown. Notice that the switch is open. Whichstatement is true.?A) The bulb has 1.5 V across it, and glows B) The bulb has 3 V across it, and glowsC) The bulb has 3 V across it, and is darkD) The bulb has 0 V across it, and is darkE) The bulb has 0 V across it, and glowsWhich statement is true if the switched is closed?Which statement is true if the switched is closed and one ofthe two batteries is reversed? + -0 AA 1.5 V + -0 AA 1.5 VCRKT-14 Two light bulbs are in series attached to a battery as shown.The bulbs are marked 40W and 60W. Which bulb is brighter?(Hints: More power = brighter. When light bulbs are in series, they have the same current. Light bulbs are intendedto operate at 120V.) A) both have same brightnessB) 40W is brighterC) 60W is brighterV 40W 60WCRKT-15 A capacitor in an RC circuit is initially charged up to a voltage of 10V and is then discharged through an R=10- resistor as shown. The switch is closed at time t=0. What is the current through the resistor, immediately after the switch is closed, at time t = 0.0+ s?A) 1A B) 0.5A C) 1/e A = 0.37A D) None of these.What is the time constant for this circuit? A) 0.01 s B) 0.1 s C) 1 s D) 10 s D) None of these.What is the current through the resistor at time t = 0.2 s?A) 1A B) 0.5A C) 1/e A = 0.37A D) None of these.I10Ω0.01 FV0 = 10VCRKT-16An RC circuit is shown below. Initially the switch is open and the capacitor has no charge. At time t=0, the switch is closed. What is the voltage across the capacitor immediately after the switch is closed (time = 0+)?A) Zero B) 10 V C) 5V D) None of these.What is the voltage across the resistor on the far right (in parallel with the capacitor) at time = 0+?A) Zero B) 10 V C) 5V D) None of these.What is the initial current "through" the capacitor (immediately after the switch is closed) ?A) 1A B) zero C) 0.5A D) None of these.A long time after the switch has been closed, what is the voltage across the capacitor?A) 5V B) 10 V C) zero D) None of these.V = 10VR = 10ΩR = 10ΩC = 0.0010 FAnswer: A) zero. Before the switch is closed, the charge Q on the capacitor is zero and the voltage across the capacitor= V = Q/C = 0. Right after the switch is closed, the charge has not had time to build up on the capacitor and the chargeand voltage are still zero.Answer: A) zero. The capacitor and the resistor on the right are in parallel and therefore have the same voltage drop across them. Since the capacitor is acting like a wire there is no voltage drop across it, which is the same for the resistor on the right. Answer: A), 1A. Initially, when the capacitor has zero charge, it behaves like a short-circuit (zero resistance) because it is easy to put charge on an uncharged capacitor. The circuit is then, effectively...The capacitor acting like a zero resistance wire which all the current flows through (initially). The other resistor is not involved in the (initial) current flow.I=V/R=10/10=1AV=10VR = 10ΩAnswer: A) 5V. After a long time, the capacitor becomes fully charged, and current stops flowing through it. When this happens it behaves like an infinite resistor, and the circuit is effectively..As far as current flow is concerned, the capacitor is gone. The voltage across the capacitor is the same as the voltage on the right, since they are in parallel. The
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