Consider a solid sphere with radius R with a charge uniformly spread throughout its volume. The magnitude of the sphere’s electric field is at a point P1 on the sphere’s surface and is at a point P2 at a distance R from the sphere’s center. In the relationship

src="https://sciemce.com/media/4/0bceea0c4116d7d2019-09-09 19_24_08-ch02_clicker [Compatibility Mode] - Microsoft PowerPoint.png" class="w-image" /> , what is the value of b?

A. 0
B. 1
C. 2
D. 4
E. 8
F. Other

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C. 2

Physics & Space Science

Because electromagnetic radiation (EMR) of sufficient energy can excite electrons from stable orbitals, EMR is considered to travel in packets of energy called _________.

Fill in the blank(s) with the appropriate word(s).

A thermocouple (0.8-mm-OD) is located horizontally in a large enclosure whose walls are at 37°C. The enclosure is filled with a transparent quiescent gas that has the same properties as air. The electromotive force (emf) of the thermocouple indicates a temperature of 230°C. Estimate the true gas temperature if the emissivity of the thermocouple is 0.8.

GIVEN
• Horizontal thermocouple in a large enclosure
• Thermocouple outside diameter (D) = 0.8 mm = 0.0008 m
• Enclosure wall temperature (Te) = 37°C = 310 K
• Gas is enclosure is quiescent and has the same properties as air
• Thermocouple reading (Ttc) = 230°C = 503 K
• Thermocouple emissivity (?) = 0.8
FIND
• True gas temperature (T?)
ASSUMPTIONS
• Enclosure behaves as a black body
• Conduction along the thermocouple out of the enclosure is negligible
SKETCH

PROPERTIES AND CONSTANTS
The Stephan-Boltzmann Constant (?) = 5.67 ?10–8 W/(m2 K4).

The ionic layers of the atmosphere reflect

a) radio waves. b) charged particles. c) sound. d) light.

What is the change of entropy associated with 3.0 kg of water freezing to ice at 0.°C?

A) -1.1 kcal/K B) -0.88 kcal/K C) 0 kcal/K D) 1.0 kcal/K E) +0.88 kcal/K