physics (thxs again)

Thank you for the help :)

A certain sample carries a current of 4A when the potential difference is 2V and a current of 10A when the potential difference is 4V. This samples is:
a) obeys ohm's law
b) has a resistance of 0.5 ohms at 1V
c) has a resistance of 2.5 ohms at 1V
d) has a resistance of 2.5ohms at 2V
e) does not have a resistance

I treated each pathway separately so I have
R= V/I = (2/4)= .5
R= V/I= (4/10) = .4
The answer says that it is B. I am not quiet seeing how they get that answer.

An certain resistor dissipates electrical energy at a rate of 0.5 W when connected to a 3V potential difference. When connected to a 1V potential difference, the rate of electrical dissipation:
a).5 W
B) .167 W
C) 1.5W
D) .056W
E) none of these

I am little unsure about how to go about this problem. The main equation I got was P= V^2/R. The question seems to only want power.



Pm the first, there is no correct answer.

On the second, Power= v^2/resistance so as voltage decreases by 1/3, power decreases by 1/9. One-ninth of .5 watts is ...

  1. 👍 0
  2. 👎 0
  3. 👁 1,064

Respond to this Question

First Name

Your Response

Similar Questions

  1. phys102

    a copper wire has a diameter of 1.02mm,the wire carries a constant current of 1.67A,the density of the free electrons is 8.5X10^28 e/m^3.calculate the current density and drift velocity

  2. physics

    The emf of a battery is equal to its terminal potential difference: A) under all conditions B) only when the battery is being charged C) only when a large current is in the battery D) only when there is no curent in the battery E)

  3. physic

    A long straight horizontal wire carries a current = 3.90 A to the left. A positive 1.00 C charge moves to the right at a distance 1.50 m above the wire at constant speed v = 5000 m/s. What is the magnitude of the magnetic field at

  4. electromagnetic

    Plane x = 10 carries current 100 mA/m along az while line x = 1, y = —2 carries filamentary current 20π mA along az Determine H at (4, 3, 2). pls i need it for my exam

  1. physics

    A long, vertical, straight wire carries a current I going upwards. The wire is perpendicular to the plane of a circular metal loop and passes through the center of the loop. The loop is allowed to fall and maintains its

  2. Physics

    A 550 turn solenoid is 15 cm long. The current in it is 33 A. A 3.0 cm long straight wire cuts through the center of the solenoid, along a diameter. This wire carries a 22 A current downward( and is connected by other wires that

  3. Physics concept question

    A long straight horizontal wire carries a current I = 2.10 A to the left. A positive 1.00 C charge moves to the right at a distance 4.50 m above the wire at constant speed v = 2250 m/s. What are the magnitude and the direction of

  4. Physics

    A long solenoid has 1400 turns per meter of length, and it carries a current of 2.0 A. A small circular coil of wire is placed inside the solenoid with the normal to the coil oriented at an angle of 90.0˚ with respect to the axis

  1. AP Physics 1

    If electrical energy costs 12 cents, or $0.12, per kilowatt-hour, how much does it cost to operate an electric over for 5.0 h if it carries a current of 20.0 A at 220 V?

  2. Science

    A cooper wire has a diameter of 1.02 mm and carries a constant current of 1.67 A. If density of free electron in copper is 8.5×10^28 m-3 calculates the current density and the drift velocity of the electron

  3. Physics

    A long coaxial cable consists of two concentric conductors. The inner conductor is a cylinder with radius R1, and it carries a current I0 uniformly distributed over its cross section. The outer conductor is a cylindrical shell

  4. science

    The half-life of carbon 14 is 5730 years. if a 1 g sample of old carbon is 1/8 as radioactive as 1 g of a current sample, then the age of the old sample is about ___________years. 22,900 17,200 11,500 716

You can view more similar questions or ask a new question.