A rod of 2.0-m length and a square (2.0 mm × 2.0 mm)cross section is made of a material with a resistivity of 6.0 × 10−8 Ω ⋅ m.If a potential difference of 0.50 V is placed across the ends of the rod,at what rate is heat generated in the rod?

A) 3.0 W B) 5.3 W C) 8.3 W D) 1.3 W E) 17 W A) 3.0 W B) 5.3 W C) 8.3 W D) 1.3 W E) 17 W C

The electron density in copper is 8.49 × 1028 electrons/m3.The electron charge is e = −1.60 × 10−19 C.When a 1.00 A current is present in a copper wire with a 0.40 cm2 cross-section,the electron drift velocity,in m/s,with direction defined relative to the current density,is

A) −1.84 × 10−6. B) +1.84 × 10−6. C) −1.84. D) −5.43 × 105. E) +5.43 × 105. A) −1.84 × 10−6. B) +1.84 × 10−6. C) −1.84. D) −5.43 × 105. E) +5.43 × 105.

A nichrome wire and an aluminum wire,each with the same initial resistance,have the same change in resistance when heated separately.(ρAl = 2.82 × 10−8 Ω ⋅ m;αAl = 3.9 × 10−3 / °C;ρnichrome = 1.50 × 10−6 Ω ⋅ m;αnichrome = 0.40 × 10−3 / °C. )The ratio of the temperature change of the nichrome wire to the temperature change of the aluminum wire is

A) 0.019. B) 0.10. C) 0.18. D) 9.8. E) 53. A) 0.019. B) 0.10. C) 0.18. D) 9.8. E) 53.

Exam 27: Current and Resistance

Explore all topics

A rod of 2.0-m length and a square (2.0 mm × 2.0 mm)cross section is made of a material with a resistivity of 6.0 × 10−⁸ Ω ⋅ m.If a potential difference of 0.50 V is placed across the ends of the rod,at what rate is heat generated in the rod?

Free

(Multiple Choice)

4.8/5

(29)

Question 1

Correct Answer:

Verified

How many electrons pass through a 20-Ω resistor in 10 min if there is a potential drop of 30 volts across it?

Free

(Multiple Choice)

4.7/5

(32)

Question 2

Correct Answer:

Verified

What maximum power can be generated from an 18-V emf using any combination of a 6.0-Ω resistor and a 9.0-Ω resistor?

Free

(Multiple Choice)

4.9/5

(33)

Question 3

Correct Answer:

Verified

Light bulb A is rated at 60 W and light bulb B is rated at 100 W.Both are designed to operate at 110 V.Which statement is correct?

(Multiple Choice)

4.9/5

(37)

Question 4

The electron density in copper is 8.49 × 10²⁸ electrons/m³.The electron charge is e = −1.60 × 10−¹⁹ C.When a 1.00 A current is present in a copper wire with a 0.40 cm² cross-section,the electron drift velocity,in m/s,with direction defined relative to the current density,is

(Multiple Choice)

4.8/5

(33)

Question 5

The temperature coefficient of resistivity of iron is 5.0 × 10−³ / °C;that of carbon is −0.50 × 10−³ / °C.When an iron wire and a carbon rod,each having the same 10 Ω resistance at 20°C,are cooled from that temperature to −80°C,the new ratio of the resistance of the carbon rod to the resistance of the iron wire at the lower temperature is

(Multiple Choice)

4.9/5

(33)

Question 6

A conductor of radius r,length And resistivity ρ has resistance R.It is melted down and formed into a new conductor,also cylindrical,with one fourth the length of the original conductor.The resistance of the new conductor is

(Multiple Choice)

4.7/5

(34)

Question 7

How much energy is dissipated as heat during a two-minute time interval by a 1.5-kΩ resistor which has a constant 20-V potential difference across its leads?

(Multiple Choice)

4.8/5

(35)

Question 8

A cook plugs a 500 W crockpot and a 1 000 W kettle into a 240 V power supply,all operating on direct current.When we compare the two,we find that

(Multiple Choice)

4.8/5

(30)

Question 9

If 5.0 × 10²¹ electrons pass through a 20-Ω resistor in 10 min,what is the potential difference across the resistor?

(Multiple Choice)

4.8/5

(32)

Question 10

A small bulb is rated at 7.5 W when operated at 125 V.Its resistance (in ohms)is

(Multiple Choice)

4.9/5

(32)

Question 11

A 4.0-Ω resistor has a current of 3.0 A in it for 5.0 min.How many electrons pass through the resistor during this time interval?

(Multiple Choice)

4.9/5

(29)

Question 12

The heating coil of a hot water heater has a resistance of 20 ohms and operates at 210 V.If electrical energy costs 5.5 cents per kW-hr,what does it cost to raise the 200 kg of water in the tank from 15°C to 80°C? (The specific heat of water is 4 186 J/kg°C)

(Short Answer)

4.8/5

(41)

Question 13

What is the resistance of 1 000 m of 4-mm diameter copper wire? (ρ_Cu = 1.7 × 10^-8 Ω ⋅ m)

(Short Answer)

4.8/5

(36)

Question 14

Jadeen says that you can increase the resistance of a copper wire by hammering the wire to make it narrower and longer.Arnell says that you can increase its resistance by heating the wire.Which one,if either,is correct,and why?

(Multiple Choice)

4.9/5

(31)

Question 15

An electric device,which heats water by immersing a resistance wire in the water,generates 50 cal of heat per second when an electric potential difference of 12 V is placed across its leads.What is the resistance of the heater wire? (Note: 1 cal = 4.186 J)

(Multiple Choice)

5.0/5

(34)

Question 16

A rod (length = 80 cm)with a rectangular cross section (1.5 mm × 2.0 mm)has a resistance of 0.20 Ω.What is the resistivity of the material used to make the rod?

(Multiple Choice)

4.9/5

(35)

Question 17

A nichrome wire and an aluminum wire,each with the same initial resistance,have the same change in resistance when heated separately.(ρ_Al = 2.82 × 10−⁸ Ω ⋅ m;α_Al = 3.9 × 10−³ / °C;ρ_nichrome = 1.50 × 10−⁶ Ω ⋅ m;α_nichrome = 0.40 × 10−³ / °C. )The ratio of the temperature change of the nichrome wire to the temperature change of the aluminum wire is

(Multiple Choice)

4.7/5

(38)

Question 18

If a mile of 24-gauge copper wire has a resistance of 0.14 kΩ and the resistivity of copper is 1.7 × 10−⁸ Ω ⋅ m,what is the diameter of the wire? (1 mile = 1.6 km)

(Multiple Choice)

5.0/5

(31)

Question 19

In the Drude model of electrical conduction,the current density is directly proportional to

(Multiple Choice)

4.8/5

(35)

Question 20

Showing 1 - 20 of 34

Exam 27: Current and Resistance

A rod of 2.0-m length and a square (2.0 mm × 2.0 mm)cross section is made of a material with a resistivity of 6.0 × 10−8 Ω ⋅ m.If a potential difference of 0.50 V is placed across the ends of the rod,at what rate is heat generated in the rod?

How many electrons pass through a 20-Ω resistor in 10 min if there is a potential drop of 30 volts across it?

What maximum power can be generated from an 18-V emf using any combination of a 6.0-Ω resistor and a 9.0-Ω resistor?

Light bulb A is rated at 60 W and light bulb B is rated at 100 W.Both are designed to operate at 110 V.Which statement is correct?

The electron density in copper is 8.49 × 1028 electrons/m3.The electron charge is e = −1.60 × 10−19 C.When a 1.00 A current is present in a copper wire with a 0.40 cm2 cross-section,the electron drift velocity,in m/s,with direction defined relative to the current density,is

A conductor of radius r,length And resistivity ρ has resistance R.It is melted down and formed into a new conductor,also cylindrical,with one fourth the length of the original conductor.The resistance of the new conductor is

How much energy is dissipated as heat during a two-minute time interval by a 1.5-kΩ resistor which has a constant 20-V potential difference across its leads?

A cook plugs a 500 W crockpot and a 1 000 W kettle into a 240 V power supply,all operating on direct current.When we compare the two,we find that

If 5.0 × 1021 electrons pass through a 20-Ω resistor in 10 min,what is the potential difference across the resistor?

A small bulb is rated at 7.5 W when operated at 125 V.Its resistance (in ohms)is

A 4.0-Ω resistor has a current of 3.0 A in it for 5.0 min.How many electrons pass through the resistor during this time interval?

The heating coil of a hot water heater has a resistance of 20 ohms and operates at 210 V.If electrical energy costs 5.5 cents per kW-hr,what does it cost to raise the 200 kg of water in the tank from 15°C to 80°C? (The specific heat of water is 4 186 J/kg°C)

What is the resistance of 1 000 m of 4-mm diameter copper wire? (ρCu = 1.7 × 10-8 Ω ⋅ m)

Jadeen says that you can increase the resistance of a copper wire by hammering the wire to make it narrower and longer.Arnell says that you can increase its resistance by heating the wire.Which one,if either,is correct,and why?

An electric device,which heats water by immersing a resistance wire in the water,generates 50 cal of heat per second when an electric potential difference of 12 V is placed across its leads.What is the resistance of the heater wire? (Note: 1 cal = 4.186 J)

A rod (length = 80 cm)with a rectangular cross section (1.5 mm × 2.0 mm)has a resistance of 0.20 Ω.What is the resistivity of the material used to make the rod?

If a mile of 24-gauge copper wire has a resistance of 0.14 kΩ and the resistivity of copper is 1.7 × 10−8 Ω ⋅ m,what is the diameter of the wire? (1 mile = 1.6 km)

In the Drude model of electrical conduction,the current density is directly proportional to

Physics and Measurement

Motion in One Dimension

Vectors

Motion in Two Dimensions

The Laws of Motion

Circular Motion and Other Applications of Newtons Laws

Energy of a System

Conservation of Energy

Linear Momentum and Collisions

Rotation of a Rigid Object About a Fixed Axis

Angular Momentum

Static Equilibrium and Elasticity

Universal Gravitation

Fluid Mechanics

Oscillatory Motion

Wave Motion

Sound Waves

Superposition and Standing Waves

Temperature

The First Law of Thermodynamics

The Kinetic Theory of Gases

Heat Engines, entropy, and the Second Law of Thermodynamics

Electric Fields

Gausss Law

Electric Potential

Capacitance and Dielectrics

Direct-Current Circuits

Magnetic Fields

Sources of the Magnetic Field

Faradays Law

Inductance

Alternating-Current Circuits

Electromagnetic Waves

The Nature of Light and the Principles of Ray Optics

Image Formation

Wave Optics

Diffraction Patterns and Polarization

Relativity

Introduction to Quantum Physics

Quantum Mechanics

Atomic Physics

Molecules and Solids

Nuclear Structure

Applications of Nuclear Physics

Particle Physics and Cosmology

Filters

A rod of 2.0-m length and a square (2.0 mm × 2.0 mm)cross section is made of a material with a resistivity of 6.0 × 10−⁸ Ω ⋅ m.If a potential difference of 0.50 V is placed across the ends of the rod,at what rate is heat generated in the rod?

The electron density in copper is 8.49 × 10²⁸ electrons/m³.The electron charge is e = −1.60 × 10−¹⁹ C.When a 1.00 A current is present in a copper wire with a 0.40 cm² cross-section,the electron drift velocity,in m/s,with direction defined relative to the current density,is

If 5.0 × 10²¹ electrons pass through a 20-Ω resistor in 10 min,what is the potential difference across the resistor?

What is the resistance of 1 000 m of 4-mm diameter copper wire? (ρ_Cu = 1.7 × 10^-8 Ω ⋅ m)

If a mile of 24-gauge copper wire has a resistance of 0.14 kΩ and the resistivity of copper is 1.7 × 10−⁸ Ω ⋅ m,what is the diameter of the wire? (1 mile = 1.6 km)