1. A length of wire of resistance Ris connected across a battery with zero internalresistance. The wire is then cut in half and the two halves are connected in parallel. When thecombination is reconnected across the battery, what happens to the resultant powerdissipated and the current drawn from the battery?PowerCurrent(A)DoublesDoubles(В)QuadruplesDoublesQuadruplesQuadruples(C)Doubles(D)Quadruples2. In the electric circuit shown at right, the current through the 2.0 Q resistor is 3.0 A. What isthe approximate emf of the battery, assuming it is ideal?(A) 63 V(В) 51 V6.00(C) 42 V(D) 36 V(E) 24 V

Answered: Image /qna-images/answer/d4235d53-9f78-4180-a4bf-1e9f0cb99e27.jpg

1. A length of wire of resistance Ris connected across a battery with zero internal resistance. The wire is then cut in half and the two halves are connected in parallel. When the combination is reconnected across the battery, what happens to the resultant power dissipated and the current drawn from the battery? (A) (B) (C) (D) Power Doubles Quadruples Doubles Quadruples Current Doubles Doubles Quadruples Quadruples 2. In the electric circuit shown at right, the current through the 2.0 O resistor is 3.0 A. What is the approximate emf of the battery, assuming it is ideal? (A) 63 V (B) 51 V (C) 42 V (D) 36 V (E) 24 V 6.00 6,00

1. A length of wire of resistance Ris connected across a battery with zero internal resistance. The wire is then cut in half and the two halves are connected in parallel. When the combination is reconnected across the battery, what happens to the resultant power dissipated and the current drawn from the battery? (A) (B) (C) (D) Power Doubles Quadruples Doubles Quadruples Current Doubles Doubles Quadruples Quadruples 2. In the electric circuit shown at right, the current through the 2.0 O resistor is 3.0 A. What is the approximate emf of the battery, assuming it is ideal? (A) 63 V (B) 51 V (C) 42 V (D) 36 V (E) 24 V 6.00 6,00

Physics for Scientists and Engineers, Technology Update (No access codes included)

9th Edition

ISBN:9781305116399

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter28: Direct-current Circuits

Section: Chapter Questions

Problem 28.9OQ: When resistors with different resistances are connected in parallel, which of the following must be...

See similar textbooks

Similar questions

When resistors with different resistances are connected in parallel, which of the following must be the same for each resistor? Choose all correct answers, (a) potential difference (b) current (c) power delivered (d) charge entering each resistor in a given time interval (e) none of those answers
An electric eel generates electric currents through its highly specialized Hunters organ, in which thousands of disk-shaped cells called electrocytes are lined up in series, very much in the same way batteries are lined up inside a flashlight. When activated, each electrocyte can maintain a potential difference of about 150 mV at a current of 1.0 A for about 2.0 ms. Suppose a grown electric eel has 4.0 103 electrocytes and can deliver up to 3.00 102 shocks in rapid series over about 1.0 s. (a) What maximum electrical power can an electric eel generate? (b) Approximately how much energy does it release in one shock? (c) How high would a mass of 1.0 kg have to be lifted so that its gravitational potential energy equals the energy released in 3.00 102 such shocks?
Review. When a straight wire is warmed, its resistance is given by R = R0,[1 + a(T T0)] according to Equation 27.20, where a is the temperature coefficient of resistivity. This expression needs to be modified if we include the change in dimensions of the wire due to thermal expansion. For a copper wire of radius 0.100 0 mm and length 2.000 m, find its resistance at 100.0C, including the effects of both thermal expansion and temperature variation of resistivity. Assume the coefficients are known to four significant figures.
Integrated Concepts (a) What energy is dissipated by a lightning bolt having a 20,000-A current, a voltage of 1.00102 MV, and a length of 1.00 ms? (b) What mass of tree sap could be raised from 18.0°C to its boiling point and then evaporated by this energy, assuming sap has the same thermal characteristics as water?
A rechargeable battery has an emf of 13.2 V and an internal resistance of 0.850 . It is charged by a 14.7-V power supply for a time interval of 1.80 h. Alter charging, the battery returns to its original state as it delivers a constant current to a load resistor over 7.30 h. Find the efficiency of the battery as an energy storage device. (The efficiency here is defined as the energy delivered to the load during discharge divided by the energy delivered by the 14.7-V power supply during the charging process.)
When a straight wire is heated, its resistance changes according to the equation R = R0 [1 + (T T0)] (Eq. 17.7), where is the temperature coefficient of resistivity. (a) Show that a more precise result, which includes the length and area of a wire change when it is heated, is R=R0[1+(TT0)][1+(TT0)][1+2(TT0)] where is the coefficient of linear expansion. (See Topic 10.) (b) Compare the two results for a 2.00-m-long copper wire of radius 0.100 mm, starting at 20.0C and heated to 100.0C.
Integrated Concepts (a) Assuming 95.0% efficiency for the conversion of electrical power by the motor, what current must the 12.0-V batteries of a 750-kg electric car be able to supply: (a) To accelerate from rest to 25.0 m/s in 1.00 min? (b) To climb a 2.00 102-m- high hill in 2.00 min at a constant 25.0-m/s speed while exerting 5.00 102 N of force to overcome air resistance and friction? (c) To travel at a constant 25.0-m/s speed, exerting a 5.00 102 N force to overcome air resistance and friction? See Figure 20.44.
When a straight wire is heated, its resistance changes according to the equation R = R0 [1 + (T T0)] (Eq. 17.7), where is the temperature coefficient of resistivity. (a) Show that a more precise result, which includes the length and area of a wire change when it is heated, is R=R0[1+(TT0)][1+(TT0)][1+2(TT0)] where is the coefficient of linear expansion. (See Topic 10.) (b) Compare the two results for a 2.00-m-long copper wire of radius 0.100 mm, starting at 20.0C and heated to 100.0C.
Review. Ail aluminum rod has a resistance of 1.23 at 20.0C. Calculate the resistance of the rod at 120C by accounting for the changes in both the resistivity and the dimensions of the rod. The coefficient of linear expansion for aluminum is 2.40 10-6 (C)-1
The human body can exhibit a wide range of resistances to current depending on the path of the current, contact area, and sweatiness of the skin. Suppose the resistance across the chest from the left hand to the right hand is 1.0 106 . (a) How much voltage is required to cause possible heart fibrillation in a man, which corresponds to 500 mA of direct current? (b) Why should rubber-soled shoes and rubber gloves be worn when working around electricity?
A portable coffee heater supplies a potential difference of 12.0 V across a Nichrome heating clement with a resistance of 2.00 . (a) Calculate the power consumed by the heater. (b) How many minutes would it take to heat 1.00 kg of coffee from 20.0C to 50.0C with this heater? Coffee has a specific heat of 4 184J/(kg C). Neglect any energy losses to the environment.
A child's electronic toy is supplied by three 1.58-V alkaline cells having internal resistances of 0.0200 inseries with a 1.53-V carbon-zinc dry cell having a 0.100- internal resistance. The load resistance is 10.0 . (a) Draw a circuit diagram of the toy and itsbatteries, (b) What current flows? (c) How much power is supplied to the load? (d) What is the internal resistance of the dry cell if it goes bad, resulting in only 0.500 W being supplied to the load?