Power: If we double the resistance in a circuit but keep the current in it constant, the power dissipated by that circuit will
A. be four times as great.
B. be two times as great.
C. be one-half as great.
D. be one-fourth as great.
Answer: B
You might also like to view...
Weight and g: ?MassRadiusOrbital radiusOrbital periodMoon A4.0 × 1020 kgunknown2.0 × 108 m4.0 × 106 sMoon B1.5 × 1020 kg2.0 × 105 m3.0 × 108 munknownMithra is an unknown planet that has two airless moons, A and B, in circular orbits around it. The table summarizes the hypothetical data about these moons. If you dropped a laser at the surface of Moon B, at what rate would it accelerate toward the ground? (G = 6.67 × 10-11 N ? m2/kg2)
A. 0.10 m/s2 B. 0.15 m/s2 C. 0.20 m/s2 D. 0.25 m/s2 E. 0.30 m/s2
Einstein's theory of relativity is based in part on which one of the following postulates?
a. Speed of light in a vacuum is same for all observers regardless of source velocity. b. Energy is conserved only in elastic collisions. c. Space and time are absolutes. d. Mass and energy are equivalent.
Two long bar magnets are aligned so that north poles face each other. The magnets are separated by 1 cm, and a repulsive force between the north poles is 0.04 N. When the separation is increased to 2 cm the force will be
A. 0.020 N. B. 0.050 N. C. 0.40 N. D. 0.025 N. E. 0.010 N.
Magnetic Field of a Long Wire: A high power line carries a current of 1.0 kA. What is the strength of the magnetic field this line produces at the ground, 10 m away? (?0 = 4? × 10-7 T ? m/A)
A. 4.7 µT B. 6.4 µT C. 20 µT D. 56 µT