An air-filled 39.1 ?H solenoid has a length 4.0 cm and cross-sectional area 0.60 cm2. How many turns are in this solenoid?
A)
1200
B)
12
C)
120
D)
144
E)
21000
D
You might also like to view...
All around the world, ancient cultures celebrated heroes, gods, and mythical beasts by naming groups of stars called _____
A) satellites B) constellations C) wormholes D) comets
Which of the following is true of the orbits of all the planets in our solar system?
a. They all orbit at the same speed. b. They are all made out of gas. c. They all orbit the Sun in the same direction. d. They have many different orbital inclinations.
A parallel plate capacitor of capacitance C0 has plates of area A with separation d between them. When it is connected to a battery of voltage V0, it has charge of magnitude Q0 on its plates. While it is connected to the battery, the space between the plates is filled with a material of dielectric constant 3. After the dielectric is added, the magnitude of the charge on the plates and the new capacitance are what?
A.
Q0, 
C0B.
C0C.
D.
E.
If a star has a mass of 10 solar masses and a luminosity of 10,000 solar luminosities, how long is its lifetime? (The Sun's lifetime is 10 billion years.)
A) 100 billion years B) 10 million years C) 1 million years D) 100 trillion years