Questions from College Physics


Q: A certain toaster has a heating element made of Nichrome resistance wire

A certain toaster has a heating element made of Nichrome resistance wire. When the toaster is first connected to a 120. - V source of potential difference (and the wire is at a temperature of 20.0°C),...

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Q: A copper cable is designed to carry a current of 300.

A copper cable is designed to carry a current of 300. A with a power loss of 2.00 W/m. What is the required radius of this cable?

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Q: Batteries are rated in terms of ampere - hours (A ·

Batteries are rated in terms of ampere - hours (A · h). For example, a battery that can deliver a current of 3.0 A for 5.0 h is rated at 15 A · h. (a) What is the total energy, in kilowatt - hours, st...

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Q: The potential difference across a resting neuron in the human body is

The potential difference across a resting neuron in the human body is about 75.0 mV and carries a current of about 0.200 mA. How much power does the neuron release?

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Q: A student drops two metallic objects into a 120-g steel

A student drops two metallic objects into a 120-g steel container holding 150 g of water at 25°C. One object is a 200-g cube of copper that is initially at 85°C, and the other is a chunk of aluminum t...

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Q: The cost of electricity varies widely throughout the United States; $

The cost of electricity varies widely throughout the United States; $0.120/kWh is a typical value. At this unit price, calculate the cost of (a) Leaving a 40.0 - W porch light on for 2 weeks while you...

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Q: An electric utility company supplies a customer’s house from the main power

An electric utility company supplies a customer’s house from the main power lines (120. V) with two copper wires, each of which is 50.0 m long and has a resistance of 0.108 Ω per 300. m. (a) Find the...

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Q: An office worker uses an immersion heater to warm 250 g of

An office worker uses an immersion heater to warm 250 g of water in a light, covered, insulated cup from 20.°C to 100.°C in 4.00 minutes. The heater is a Nichrome resistance wire connected to a 120 -...

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Q: Two wires A and B made of the same material and having

Two wires A and B made of the same material and having the same lengths are connected across the same voltage source. If the power supplied to wire A is three times the power supplied to wire B, what...

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Q: A certain laboratory experiment requires an aluminum wire of length of 32

A certain laboratory experiment requires an aluminum wire of length of 32.0 m and a resistance of 2.50 Ω at 20.0°C. What diameter wire must be used?

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