Current Electricity Questions and Answers

Consider the circuit shown below 1 Using only symbols write an equation based on the current junction rule current continuity at point A 2 Using only symbols write TWO equations based o the voltage loop rule for the left and right loops 3 Suppose that R 10 Ohms R 15 Ohms R3 20 Ohms and R4 30 Ohms The EMF on Battery 1 is 24 Volts and the EMF on Battery 2 is 12 Volts What is the current through R4 What is the potential at point B 1 E1 R www ww R a www b R3 1 M E2 R

A series circuit contains one 30 ohm resistor one 50 ohm resistor and a 100 volt battery It includes an ammeter such that it reads the current passing through the circuit and a voltmeter such that it reads the voltage drop across the 50 ohm resistor a Sketch this circuit b Determine the equivalent resistance of the circuit C d e f 800 Calculate the amount of current flowing through the circuit 1 25 A Calculate the voltage drop across the 50 ohm resistor 62 5 V Compare the current passing through the 30 ohm resistor to the current passing through the 50 ohm resistor Compare the voltage drop across the 30 ohm

5 The length of a copper wire is cut in half By what factor does the resistance change DA 1 4 OB 1 2 DC 2 OD 4 DE I need help IM Series Circuit 14 What diameter of 100 m long copper wire would have a resistance of 0 1002 Por 1 68x10 m O 2 2 mm O 3 7 mm O 4 6 mm O 5 4 mm O I need help 16 The radius of a copper wire is doubled By what factor does the resistivity change OA 1 4 OB 1 2 OC 1 OD 2 OE I need help

2 A circuit has 3 A of current How long does it take 45 C of charge to travel through the circuit OA 3 S OB 5 S OC 15 s OD 20 s OE I need help Cougrietota Circuits Law 1 12 C of charge passes a location in a circuit in 10 seconds What is the current flowing past the point O 1 2 A O 3 3 A 4 8 A O 5 0 A O I need help BLIGE 3 A circuit has 2 5 A ofcurrent How much charge travels through the circuit after 4s OA 2 C OB 4C OC 8 C OD 10 C

The resistors in the circuit below have the following valu

5 How much voltage is needed in order to produce a 0 70 A current through a 490 Q resistor OA 114 V OB 267 V OC 343 V OD 408 V OE I need help Power 4 25 A flashlight has a resistance of 25 2 and is connected by a wire to a 120 V source of voltage What is the current in the flashlight OA 3 2 A OB 4 8 A OC 5 5 A OD 7 1 A OE I need help geen 6 What is the resistance of arheostat coil if 0 05 A of current flows through it when 6 V is applied across it O 1200 O 2200 O 240 Q O 3100 OI need help 10 8

A home uses 400 kWh of electricity during peak hours and 300 kWh during off-peak hours. The power company charges 15¢/kWh for peak consumption and 10¢/kWh for off-peak use. How much is the homeowner's energy bill? Show all your calculations for full mark.

A resistor is measured to have a resistance of 252 Q. What is the potential difference across the resistor when it carries a current of 75.0 mA? 18900 V 16.4 V 3.36 V 18.9 V

What is the potential difference across the terminals of a battery if 45 kJ of energy is required to move 500.0 C of charge? 0.090 V 22 500 V 90 V 9.0 V

Two identical batteries each of emf E = 2 volt and internal resistance r = 1 ohm are available to produce heat in an exlernal resistance by passing a current through it. What is the maximum power that can be developed across an external resistance R using these batteries. A. 4W B. 8W C. 6W D. 2W

The resistivity of gold is 2.44 × 10-8 • m at a temperature of 20°C. A gold wire, 1.8 mm in diameter and 14 cm long, carries a current of 480 mA. The power dissipated in the wire is closest to: B) 0.31 mW C) 0.077 mW D) 0.19 mW A) 0.14 mW

A motor is 80% efficient. How much usefull work can the motor do if it is supplied with 200kW.h of energy?

Show that the drift speed of free electrons in a wire does not depend on the cross-sectional area of the wire.

The heater element of a particular 120-V toaster is a 8.9-m length of nichrome wire, whose diameter is 0.86 mm. The resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6. m. If the toaster is operated at a voltage of 120 V, how much power does it draw? 800 W 750 W 700 W 770 W 720 W

When you attach a 1.00 m long section of wire to the ends of a 1.50 V battery you measure the current in the wire to be 8.00 A. If the diameter of the wire is 3.33 x 10-4m, what is its resistivity?

In the circuit below, all four resistors are identical (R₁ = R₂ = R3 = R₁ = R) and the battery has a voltage of 4.82 V. (a) When the switch is placed in position 1, the measured current in the battery is 1.39 mA. What is the value of each resistor? (b) When the switch is placed in position 2, what is the current flowing out of the battery? (c) When the switch is open (neither in position 1 or position 2), what is the current flowing out of the battery?

The length of a certain wire is kept same while its radius is doubled. What is the new resistivity of this wire? E) It does not change. C) It is reduced by a factor of 2. B) It is increased by a factor of 4. D) It is reduced by a factor of 4. A) It is increased by a factor of 2.

Equal potentials are applied on an iron and a copper wire of same length. In order to have the same current flow in the two wires, the ratio r (iron) / r (copper) of their radii must be : [Give that : specific resistance of copper = 1.7 x 10-8 ohm - m ]:

Which of these statements is true about resistors connected in series? Both the current passing through and the potential drop across each resistor are different. The same amount of current will pass through each resistor. Both the current passing through and the potential drop across each resistor are the same. The potential drop across each resistor will be the same.

A small insect crawls in the direction of electron drift along copper wire that carries a current of 2.56A. It travels with drift speed of the electron in the wire of uniform cross- section area 1 mm² . Number of free elections for copper = 8 x 1022 /cc and resistivity of copper = 1.6 × 10-Nm . How much time would the insect take to crawl 1.0 cm if it crawls at the drift speed of the electons in the wire?

Three charges are arranged in the (x, y) plane as shown. What is the magnitude of the resulting force (in nano-Newtons) on the -9 nC charge at the origin? The Coulomb constant is 8.98755 x 10 N·m²/C² Answer in units of N. part 2 of 2 What angle does the resultant force on the -9 nC charge at the origin make with the positive axis? Quadrant I lies between (f and 90°, quadrant II between between 90° and 180 etc. Answer in units of degs.

Four resistors are arranged in a circuit, as shown. There is a constant voltage Vacross the voltage source. The current / is 0.25 ampere. (a) Find the equivalent resistance of the four resistors. (b) Find the voltage Vacross the voltage source. (c) Find the voltage across resistor R₂. d) Find the power dissipated by resistor R₂.

(a) What is the hot resistance of a 28.0 W light bulb with a tungsten filament that runs on 120 V AC? (b) If the bulb's operating temperature is 2700°C, what is its resistance at 2590°C? The temperature coefficient of resistivity of tungsten is 4.50 x 10-3 °C-1.

You are planning a circuit where you need a resistor with a value of 5.13 Ohms (2) This resistor is made out of silver (see the table in your textbook for information about silver). This resistor will be cylindrical with a radius of 2.28 μm. You can assume that the resistor is being used at the standard 20 degrees Celsius. What length must your resistor be in order to have the needed resistance of 5.13 Ohms? Make sure to put your answer in an appropriate number of significant figures. Put your answer in to the box in units of cm.

A resistor with an unknown value (R) has 9V applied to it from a battery. The resistor wastes 1.34 W of power as heat. a. What is the current flowing through the resistor? b. What is the resistance of R? c. If R was powered by a 12V battery, how much power will be dissipated as heat? d. Can you think of an example were we use resistive elements for heating?

Physics students are debating the proper method for measuring electric current and potential difference in a circuit: Group A: The ammeter measures current and is hooked up in parallel. The voltmeter measures potential difference and is hooked up in series. Group B: The ammeter measures current and is hooked up in series. The voltmeter measures potential difference and is hooked up in parallel. Group C: The ammeter measures potential difference and is hooked up in parallel. The voltmeter measures current and is hooked up in series. Which group has the best answer? (AKS 8c2) Group A Group B Group C None of the answers are accurate.

Several unequal resistors are connected in parallel. Which statement is correct about the equivalent resistance? The equivalent resistance depends on the voltage applied across the group. The equivalent resistance is less than any of the resistances in the group. The equivalent resistance is greater than any of the resistances in the group. None of these statements is correct.

A length of wire is cut in half and the two lengths are wrapped together side by side to make a thicker wire. How does the resistance of this new wire compare to the resistance of the original one? A.The new wire has four times the resistance of the original one. B.The new wire has twice the resistance of the original one. C.The new wire has one-quarter the resistance of the original one. D.The new wire has half the resistance of the original one. E.The new wire has the same resistance of the original one.

Two resistors are connected in parallel. If the battery produces 6 A, and one resistor experiences a current of 4 A, then the current in the second resistor is?

What is another way to determine voltage, current and resistance without using Ohm's Law? l. We can use Coulumbs law II. Measure the current and multiply it by the voltage III. You must use Ohm's Law to determine the third parameter IV. Measure each with a multi-meter

An electric heater is constructed by applying a potential difference of 110 V across a Nichrome wire that has a total resistance of 28.9 ohms. The power rating of the heater. I. 0.27 Watts II. 3179 Watts III. 138.9 Watts IV. 418.7 Watts

An electric heater is constructed by applying a potential difference of 120 V across a the wire Nichrome wire that has a total resistance of 8.00 V. Find the current carried and the power rating of the heater.

The electrical force between charges is strongest when the charges are Select one: a. close together. b. The electric force is constant everywhere. c. far apart.

The units used to measure charge, current, potential difference, and resistance are, respectively, d. ampere, joule, volt, ohm a. ampere, joule, ohm, volt b. coulomb, ampere, volt, ohm c. coulomb, ampere, ohm, watt e. ampere, coulomb, ohm, volt

Charged objects interact with one another. One can observe the interactions and infer information about the type of charge present on an object. Complete the following statements with the word attract or repel to illustrate your understanding of the three types of charge interactions: a. Oppositely-charged objects b. Like-charged objects c. A charged object and a neutral object will

Formula Based Problem i. Draw a working circuit with one battery and two resistors in parallel. ii. Label the battery as 16V and the two resistors as 12Ω and 60Ω. iii. What is the current going through the 12Ω resistor? iv. What is the total power being used by the circuit?

Two simple circuits are built with two different electrical devices. Each contains the same size battery. One device has a resistance of 100 2 and the other has a resistance of 1000 2. Which circuit has more current? Use the concept of resistance to explain why. Let's assume we have a battery of 1000 V. We could choose any size but 1000 V makes the math kind a simple.

Below are two sets of batteries and bulbs. In Figure 1, draw where wires must be connected in order for the bulbs to be in parallel. In Figure 2, draw where wires must be connected in order for the bulbs to be in series. Draw your wires such that they do not split or cross.

Three different circuits are set up involving identical batteries and identical bulbs. Circuit 1 connects just a single bulb to the battery. Circuit 2 connects the two bulbs in series to the battery Circuit 3 connects the two bulbs in parallel to the battery. Which battery will run out of chemical potential energy first? The battery in Circuit 1 The battery in Circuit 2 The battery in Circuit 3 The batteries in Circuit 2 and Circuit 3 tie

A high resistance resistor and a lower resistance resistor. Are connected in parallel voltage source. Which resistor has a greater power dissipation? They have the same power dissipation because they are in parallel. The higher is distance one has greater power dissipation. The lower resistance one has greater power dissipation.

Wire 1 is made of a material with resistivity p. The diameter of wire 1 is D, the length is L and the resistance is R. Wire 2 is made from a material with a resistivity 2p and the wire has a diameter 2D. What length must wire 2 have so that its resistance is the same as that of wire 1? A. L/2 B. 2L C 4L D. L/4 E 8L

An aluminum wire has a diameter of 0.102 mm and a length of 52.7 m. The resistivity of aluminum is 2.65 x 10-80-m. a) What is the resistance of the aluminum wire? b) The aluminum wire is connected end to end to an iron wire to make one long wire. The iron wire has a diameter of 0.742 mm and a length of 31.7 m. The resistivity of Iron is 20.0 x 10-80-m. What is the total resistance of the two connected wires? A. Resistance of aluminum wire is 85.7 Ω B. Resistance of aluminum wire is 16.2 Ω C. Resistance of aluminum wire is 134 Ω D. Resistance of aluminum wire is 171 Ω E. Resistance of aluminum wire is none of these answers F. Total resistance is 93.0 G. Total resistance is 186 Ω H. Total resistance is 84.7 Ω I. Total resistance is 13.5 Ω J. Total resistance is none of these answers

You have a long uniform wire with resistance R. You cut it into three equal length pieces. You connect the three pieces side by side. What is the resistance of this arrangement? A. R/6 B. 3R C. R/9 D. None of these answers E. R/3

The ends of a wire are connected to the terminals of a battery. For which of the following changes will the resulting current in the circuit have the largest value? A. Replace the wire with one that has a larger radius. B. Replace the wire with one that has a longer length. C. Replace the wire with one that has a larger resistivity.

14. Two metal rods, A and B, have the same resistance R. Rod B has three times the length and three times the diameter of rod A. Rod A has a resistivity pA related to that of rod B by: a) pA= pB emm b) pA=3 pB c) pA=1/9 pB d) pA=1/3 pB e) pA=9pB

Consider a real battery with an internal resistance of r = 10 02 and an emf of ε = 9V. The battery is connected to a load resistance of RL = 440 N. How much power is delivered to the load resistance? a) 0.184 W b) 0.176 W c) 0.02 W d) 0.004 W e) 0.18 W

Which quantities are equal to sum of the individual values within a circuit? the current in a parallel circuit and the voltage in a series circuit the resistance in a parallel circuit and the current in a series circuit the resistance in a parallel circuit and the voltage in a series circuit the voltage in a parallel circuit and the resistance in a series circuit

15. 0.01 A causes involuntary muscle contractions. The resistance of dry human skin is about 500,000 ohms and wet, sweaty, human skin is about 1000 ohms. How much voltage is required to cause involuntary muscle contractions on dry skin? *

How long must a 0.50-mm-diameter aluminum wire be to have a 0.46 A current when connected to the terminals of a 1.5 V flashlight battery? Express your answer to two significant figures and include the appropriate units. ▾ Part B Request Answer HA Units Value DINO What is the current if the wire is half this length? Express your answer to two significant figures and include the appropriate units. ? Units ?

What is the potential difference across a 16-m-long, 2.0-mm-diameter copper wire carrying an 7.3 A current? Express your answer to two significant figures and include the appropriate units.