Spherical Mirrors: When a person stands 40 cm in front of a cosmetic (concave) spherical mirror, the upright image is twice the size of the object. What is the focal length of the mirror?
A. 27 cm
B. 40 cm
C. 80 cm
D. 160 cm
Answer: C
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Parallel-Plate Capacitor: An ideal air-filled parallel-plate capacitor consists of plates that are 1.0 mm apart and have an area of 1.5 × 10-4 m2. The capacitor is connected to a 12-V potential source (battery). (?0 = 8.85 × 10-12 C2/N ? m2)(a) What is the capacitance of this capacitor?(b) How much charge is on each of its plates?(c) What is the strength of the electric field between the plates?
What will be an ideal response?
Compared with an alcohol barometer, the column height for a mercury barometer would be
A) lower. B) higher. C) the same.
A solar cell has a light-gathering area of 10 cm2 and produces 0.30 A at 0.80 V (DC) when illuminated with sunlight of intensity 1000 W/m2 . What is the efficiency of the solar cell?
a. 16% c. 7% b. 4% d. 24%
Two particles, each having a mass of 3.0 mg and having equal but opposite charges of magnitude 5.0 nC, are released simultaneously from rest when the two are 5.0 cm apart. What is the speed of either particle at the instant when the two are separated by 2.0 cm?
a. 2.1 m/s b. 1.5 m/s c. 1.8 m/s d. 2.4 m/s e. 3.2 m/s