An instrument is rated at 250 W if it is connected across a 120-V dc power supply

(a) What current does it draw under normal operation?
(b) What is its resistance?
(c) How many kilowatt-hours does it use in a day if it is left on all the time?


(a) 2.1 A (b) 58 Ω (c) 6.0 kWh

Physics & Space Science

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The electric field has a magnitude of 3.00 N/m at a distance of 60.0 cm from a point charge. What is the charge?

A. 1.40 nC B. 120 pC C. 36.0 mC D. 12.0 ?C E. 3.00 nC

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X-rays easily penetrate Earth's atmosphere and reach the ground from space

a. True b. False Indicate whether the statement is true or false

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Energy in the Electric Field: A tiny particle carries a charge of 6.0 ?C. What is the energy density in the electric field at a distance of 4.0 m from this charge? (?0 = 8.85 × 10-12 C2/N ? m2, k = 1/4??0 = 9.0 × 109 N ? m2/C2)

A. 0.050 mJ/m3 B. 0.20 mJ/m3 C. 0.81 mJ/m3 D. 3.2 mJ/m3

Physics & Space Science

Infrared radiation causes your skin to tan

a. True b. False Indicate whether the statement is true or false

Physics & Space Science