A generator coil rotates through one revolution 60 times each second. The frequency of the emf is
A) 120 Hz.
B) 60 Hz.
C) 60 Hz.
D) 30 Hz.
E) (60/ ) Hz.
B
You might also like to view...
Intensity: An 800-kHz sinusoidal radio signal is detected at a point 2.1 km distant from a transmitter tower. The electric field amplitude of the signal at that point is 0.80 V/m. Assume that the signal power is radiated uniformly in all directions and that radio waves incident upon the ground are completely absorbed. What is the intensity of the radio signal at that point? (?0 = 8.85 × 10-12 C2/N ? m2, ?0 = 4? × 10-7 T ? m/A, c = 3.0 × 108 m/s)
A. 8.5 × 10-4 W/m2 B. 1.2 × 10-3 W/m2 C. 1.7 × 10-3 W/m2 D. 6.0 × 10-4 W/m2 E. 4.2 × 10-4 W/m2
The Milky Way:
A) contains less than 50 billion stars. B) stretches across for just around 30,000 light-years. C) is known for being very unique. D) is larger than most other galaxies.
A ___________________ binary is shown in the above simulated spectra
a. single-lined spectroscopic
b. double-lined spectroscopic
c. visual
d. eclipsing
What is a quasar?
A) a starlike object that actually represents a bright patch of gas in the Milky Way B) a very large galaxy thought to be formed by the merger of several smaller galaxies, typically found in the center of a galaxy cluster C) a specialized astronomical instrument for observing distant stars D) the extremely bright center of a distant galaxy, thought to be powered by a supermassive black hole E) another name for very bright stars of spectral type O