Gauss's law, 1

A rectangular loop is held perpendicular to a uniform E-field (the loop's normal vector, dA, is parallel to the E-field direction). At what angle to its normal does the loop have to be turned through so the electric flux is one half of its original value?

• 15 degrees

• 30 degrees

• 45 degrees

• 60 degrees

• 90 degrees

The normal vector to a rectangular loop makes an angle of 35 degrees with the vector describing the direction of an applied electric field. What is the Electric Flux through the loop, given the following data? E = 52,000 N/C, width = 35 cm, length = 75 cm

• 1.1 x 10^4 Nm*m/C

• 7.8 x 10^3 Nm*m/C

• 1.1 x 10^8 Nm*m/C

• 7.8 x 10^7 Nm*m/C

• zero

A positive charge is enclosed by a spherical surface. What direction is the electric flux relative to the surface/

• tangent

• from the inside to the outside of the surface

• from the outside to the inside of the surface

• the lines do not pass through the surface

A charge of magnitude, q, is at the center of a sphere of radius r. What is the electric flux at the surface of the sphere? r = 0.53 m, q = 5.0 x 10^-6 C

• 5.6 x 10^5 Nm*m/C

• 6.5 x 10^5 Nm*m/C

• 7.3 x 10^5 Nm*m/C

• 1.1 x 10^6 Nm*m/C

• 1.3 x 10^6 Nm*m/C

You are trying to calculate the e-field outside a positive line of charge. The Gaussian surface should be what kind of geometrical object?

• circle

• cylinder

• cube

• sphere

• rectangle

A metal sphere of radius R is given a positive charge, q. What is the electric field at a distance r from the center, where r > R?

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A solid non-conducting sphere has a radius R and a charge of +Q uniformly distributed throughout its volume. Which graph below describes the electric field as a function of distance r from the center of the sphere?

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A conducting sphere has a charge +Q and a radius R. Which graph below describes the electric field as a function of distance r from the center of the sphere?

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The diagram below shows two charged plates placed close to each other. Rank the points 1, 2 and 3 from greatest to the least electric field.

• 1 larger than 2 larger than 3

• 3 larger than 1 larger than 2

• 3=2 larger than 1

• 1=2=3

A cylindrical wastepaper basket with a 0.15-m radius opening is in a uniform electric field of 300 N/C, perpendicular to the opening. The total flux through the sides and bottom is: 

• 0 N×m²/C
• 4.2 N×m²/C
• 21 N×m²/C
• 280 N×m²/C