Question 1

Consider two copper wires of equal length. One wire has twice the cross-sectional area of the other. How do the resistances of these two wires compare?

Accepted Answer

A)  The thicker wire has twice the resistance of the thinner wire. 
B)  The thicker wire has eight times the resistance of the thinner wire. 
C)  The thicker wire has one-half the resistance of the thinner wire. 
D)  The thicker wire has four times the resistance of the thinner wire. 
E)  The thicker wire has one-fourth the resistance of the thinner wire. 
A)  The thicker wire has twice the resistance of the thinner wire. 
B)  The thicker wire has eight times the resistance of the thinner wire. 
C)  The thicker wire has one-half the resistance of the thinner wire. 
D)  The thicker wire has four times the resistance of the thinner wire. 
E)  The thicker wire has one-fourth the resistance of the thinner wire.

Question 2

If the length and diameter of a wire of circular cross section are both tripled, the resistance will be

Accepted Answer

A)  unchanged. 
B)  tripled. 
C)  increased by a factor of 9. 
D)  1/3 of what it originally was. 
E)  1/9 of what it originally was. 
A)  unchanged. 
B)  tripled. 
C)  increased by a factor of 9. 
D)  1/3 of what it originally was. 
E)  1/9 of what it originally was.

Question 3

When a thin copper wire that is 178 m long is connected between a 1.2-V potential difference, a current of 2.0 amps flows through the wire. What is the diameter of this wire? The resistivity of copper is 1.72 × 10-8 Ω ∙ m.

Accepted Answer

Question 4

An electronic component with a 17-Ω resistor is rated for use at power levels not exceeding 14$ {~W}$ How much current can safely flow through the component?

Accepted Answer

A)  0.91 A 
B)  1.21 A 
C)  238 A 
D)  0.22 A 
A)  0.91 A 
B)  1.21 A 
C)  238 A 
D)  0.22 A

Question 5

A 10-A current flows through a wire for 2.0 min. (e = 1.60 × 10-19 C)
(a) How much charge has passed through this wire?
(b) How many electrons have passed any point in the wire?

Accepted Answer

(a) 1200 C

Consider two copper wires of equal length. One wire has twice the cross-sectional area of the other. How do the resistances of these two wires compare?

If the length and diameter of a wire of circular cross section are both tripled, the resistance will be

When a thin copper wire that is 178 m long is connected between a 1.2-V potential difference, a current of 2.0 amps flows through the wire. What is the diameter of this wire? The resistivity of copper is 1.72 × 10^-8Ω ∙ m.

An electronic component with a 17-Ω resistor is rated for use at power levels not exceeding 14 ${~W}$ How much current can safely flow through the component?

A 10-A current flows through a wire for 2.0 min. (e = 1.60 × 10^-19C) (a) How much charge has passed through this wire? (b) How many electrons have passed any point in the wire?

Representing Motion

Motion in One Dimension

Vectors and Motion in Two Dimensions

Forces and Newtons Laws of Motion

Applying Newtons Laws

Gravity

Rotational Motion

Equilibrium Ad Elasticity

Momentum

Energy and Work

Using Energy

Thermal Properties of Matter

Fluids

Oscillations

Traveling Waves and Sound

Superposition and Standing Waves

Wave Optics

Ray Optics

Optical Instruments

Electric Fields and Forces

Electric Potential

Circuits

Magnetic Fields and Forces

EM Induction and Em Waves

AC Electricity

Relativity

Quantum Physics

Atoms and Molecules

Nuclear Physics

Filters

Exam 22: Current and Resistance

Consider two copper wires of equal length. One wire has twice the cross-sectional area of the other. How do the resistances of these two wires compare?

If the length and diameter of a wire of circular cross section are both tripled, the resistance will be

When a thin copper wire that is 178 m long is connected between a 1.2-V potential difference, a current of 2.0 amps flows through the wire. What is the diameter of this wire? The resistivity of copper is 1.72 × 10-8 Ω ∙ m.

An electronic component with a 17-Ω resistor is rated for use at power levels not exceeding 14 W {~W} W How much current can safely flow through the component?

A 10-A current flows through a wire for 2.0 min. (e = 1.60 × 10-19 C) (a) How much charge has passed through this wire? (b) How many electrons have passed any point in the wire?

Representing Motion

Motion in One Dimension

Vectors and Motion in Two Dimensions

Forces and Newtons Laws of Motion

Applying Newtons Laws

Gravity

Rotational Motion

Equilibrium Ad Elasticity

Momentum

Energy and Work

Using Energy

Thermal Properties of Matter

Fluids

Oscillations

Traveling Waves and Sound

Superposition and Standing Waves

Wave Optics

Ray Optics

Optical Instruments

Electric Fields and Forces

Electric Potential

Circuits

Magnetic Fields and Forces

EM Induction and Em Waves

AC Electricity

Relativity

Quantum Physics

Atoms and Molecules

Nuclear Physics

Filters

When a thin copper wire that is 178 m long is connected between a 1.2-V potential difference, a current of 2.0 amps flows through the wire. What is the diameter of this wire? The resistivity of copper is 1.72 × 10^-8Ω ∙ m.

An electronic component with a 17-Ω resistor is rated for use at power levels not exceeding 14 ${~W}$ How much current can safely flow through the component?

A 10-A current flows through a wire for 2.0 min. (e = 1.60 × 10^-19C) (a) How much charge has passed through this wire? (b) How many electrons have passed any point in the wire?