# Current Electricity Questions and Answers

Physics
Current Electricity
When a resistor with resistance R is connected to a 1.50 V flashlight battery, the resistor consumes 0.0605 W of electrical power. (Throughout, assume that each battery has negligible internal resistance.) Part A What power does the resistor consume if it is connected to a 12.6 V car battery? Assume that R remains constant when the power consumption change Express your answer with the appropriate units. P= μA Value h → Units PAC ?
Physics
Current Electricity
A circuit has a current of 3.6 A and a resistance of 5.0 Q. What is the voltage applied to the circuit? O 0.72 Volts O 1.4 Volts 8.6 Volts O 18 Volts For a constant voltage, how is the resistance related to the current? 2p 2 O Resistance is inversely proportional to current, so when the resistance doubles, the current is cut in half. O Resistance is directly proportional to current, so when the resistance doubles, the current is cut in half. O Resistance is inversely proportional to current, so when the resistance doubles, the current doubles. O Resistance is directly proportional to current, so when the resistance doubles, the current doubles.
Physics
Current Electricity
Identify the end terminals and the wiper terminal for the potentiometer below. Number them 1, 2 and 3 with 2 being the wiper. What is the different between fixed- value resistor and potentiometer?
Physics
Current Electricity
Which statement correctly describes the formation of an electric current? O A resistance causes electric charges to move from lower to higher potential. O A voltage causes electric charges to move from lower to higher potential. O A resistance causes electric charges to move from higher to lower potential. OA voltage causes electric charges to move from higher to lower potential.
Physics
Current Electricity
A. A 12.0 V storage battery is connected to three resistors of 6.75 2, 15.3 2, and 21.6 2. The resistors are joined in series. a. Calculate the equivalent resistance of the circuit and the total power lost by resistors in the circuit.
Physics
Current Electricity
A certain laboratory experiment requires an aluminum wire of length of 39.0 m and a resistance of 4.10 2 at 20.0°C. What diameter wire must be used? (The resistivity of aluminum at 20.0°C is 2.82 x 10-8. m.)
Physics
Current Electricity
Imagine that you want to make sure the battery for your string of lights will last as long as possible. A battery will last longer if it powers a circuit with low current. How could you hook up a battery and 2 light bulbs so the least amount of current flows through the battery? Use the measurement tools in the simulation to check your design. 1. Insert images to illustrate that your circuit works as expected. 2. Explain why you think it works.
Physics
Current Electricity
An electric kettle with an effective resistance of 9.62 when connected to a 120 V wall outlet. How much time will it take for this kettle to convert 310,000 J of electrical energy into thermal energy (the amount of energy required to bring 1 liter of water from room temperature to a boil)?
Physics
Current Electricity
Two batteries of 7 volt and 13 volt and internal resistances 1 ohm and 2 ohm respectively are connected in parallel with a resistance of 12 ohm. Find the current through each branch of the circuit and the potential difference across 12-ohm resistance.
Physics
Current Electricity
All household circuits are wired in parallel. A 1220-W toaster, a 200-W blender, and a 50-W lamp are plugged into the same outlet. (The three devices are in parallel when plugged into the same outlet.) Assume that this is the standard household 120-V circuit with a 15-A fuse. (a) What current is drawn by each device? (b) To see if this combination will blow the 15-A fuse, find the total current used when all three appliances are on.
Physics
Current Electricity
As shown on the left, a charge Q = -8.13 mC which has a mass m = 0.270 kg is traveling with a velocity Vo = 5.61 m/s +x. The charge enters a potential difference (AV) as shown. What is the value of the potential difference needed to bring the charge to rest? Also, is the left side more positive or more negative in order to slow the charge down bringing it to rest? Select one: a. 93.2 V, Left Side is Positive b. 93.2 V, Right Side is Positive c. 523. V, Left Side is Positive d. 523. V, Right Side is Positive
Physics
Current Electricity
If all of the dimensions of the block double (to become 20 cm wide, 8 cm tall, and 6 cm deep), what happens to the resistance along each axis? A. The resistance quadruples. B. The resistance doubles. C. The resistance stays the same. D. The resistance is halved. E. The resistance is quartered.
Physics
Current Electricity
Consider the network of four resistors shown in the diagram, where R₁ = 2.00Ω , R₂ = 5.00Ω, R = 1.00Ω, and R₁ =7.00 Ω. The resistors are connected to a constant voltage of magnitude V. Find the equivalent resistance Rc of the resistor network described in Part B when the switch is closed.
Physics
Current Electricity
A gold wire 6.30 m long and of diameter 0.830 mm carries a current of 1.19 A. Find the resistance of this wire.
Physics
Current Electricity
A voltage of 56 Vis placed across a resistance of 11.2 Q. What is the current that will be pushed through the circuit?
Physics
Current Electricity
The heating element of an electric fire has a working temperature of 750°C, at which it takes 1 kW when operating from a 250 V supply. When first switched on, it takes an initial current of 6.5 A when the air temperature is 20°C. Determine the temperature coefficient of resistance of the material at 0°C.
Physics
Current Electricity
A tungsten-filament lamp has a temperature of 2050°C and a resistance of 500 ohms when taking normal working current. Calculate the resistance of the filament when it has a temperature of 25°C. Temperature coefficient of resistance of tungsten at 0°C = 0.005/°C.
Physics
Current Electricity
Interface Conditions for Permeable Materials. An interface between free space and a perfectly permeable material exists. In free space (1), μ = o [H/m], e o [F/m], and 6-0. In the permeable material (2), μ = ∞, o=0, and e Eo. Define the interface conditions at the interface between the two materials.
Physics
Current Electricity
If a metal wire carries a current of 84.0 mA, how long does it take for 12.0x10^20 electrons to pass a given cross-sectional area anywhere along the wire? The fundamental charge is 1.602 × 10^-19 C. Answer in units of s.
Physics
Current Electricity
If you had the 10 V supply set to its full voltage and set so that the maximum supply current is 5A, use Ohm's law to answer the following question. If a 2k resistor were connected across the 6V supply's terminals, the current that would flow in the resistor is _____ (in mA))
Physics
Current Electricity
Let's take a current-carrying cable with a gradually narrowing cross-sectional area along the length of the wire so the wire turns into the shape of a very long, truncated cone. How does the drift speed (va) vary along the length of the wire? Ova first increases and then goes down after it reaches to a critical value. Ova remains the same regardless the cross section of the cable. O It speeds up with the length O It slows down with the length of the cable
Physics
Current Electricity
Which of the following statements is true about electrical outlets in child care facilities? A. They should have protective covers to prevent children from sticking objects in them. B. They pose no safety hazard for children. C. They should be clearly marked so children will stay away from them. D. They should all be placed above et so young children cannot reach them.
Physics
Current Electricity
A computer monitor uses 1.5 A of current when it is plugged into a 120 V outlet. The monitor is never turned off. What is the yearly cost of operating the monitor if the cost of electricity is \$0.14/kWh? A. \$220 B. \$81 C. \$64 D. \$190 E. \$110
Physics
Current Electricity
The resistance values are R₁ =4Ω R₂=4Ω R3 = 2Ω Determine the equivalent resistance (for the combination of three resistors), the voltmeter readings and the ammeter readings at the indicated locations.