Showing 1 to 10 of 410 Questions
  • (a) A 115-g mass of aluminum is formed into a right circular cylinder, shaped so that its diameter equals its height. Calculate the resistance between the top and bottom faces of the cylinder at 20°C. (b) Calculate the resistance between opposite faces if the same mass of aluminum is formed into a cube.

    0
    280
  • (a) A 34.5-m length of copper wire at 20.0°C has a radius of 0.25 mm. If a potential difference of 9.0 V is applied across the length of the wire, determine the current in the wire. (b) If the wire is heated to 30.0°C while the 9.0-V potential difference is maintained, what is the resulting current in the wire?

    0
    529
  • (a) A sheet of copper (ρ = 1.7 × 10–8 Ω ∙ m) is 2.0 mm thick and has surface dimensions of 8.0 cm × 24 cm. If the long edges are joined to form a tube 24 cm in length, what is the resistance between the ends? (b) What mass of copper is required to manufacture a 1 500-m-long spool of copper cable with a total resistance of 4.5

    0
    267
  • (a) At room temperature what is the strength of the electric field in a 12-gauge copper wire (diameter 2.05 mm) that is needed to cause a 2.75-A current to flow? (b) What field would be needed if the wire were made of silver instead?

    1
    1641
  • (a) At what temperature would the resistance of a copper conductor be double its resistance at 20.0°C? (Use 20.0°C as the reference point in Eq.26-17; compare your answer with Figure)(b) Does this same "doubling temperature" hold for all copper conductors, regardless of shape or size?

    0
    501
  • (a) Determine the resistance of a lightbulb marked 100 W @ 120 V. (b) Assuming that the filament is tungsten and has a cross-sectional area of 0.010 mm2, determine the length of the wire inside the bulb when the bulb is operating. (c) Why do you think the wire inside the bulb is tightly coiled? (d) If the temperature of the tungsten wire

    0
    350
  • (a) Find the individual monthly (30-day) electric energy costs (to the nearest dollar) for each of the following household appliances if the utility rate is $0.12/kWh: central air conditioning that runs 30% of the time; a blender that is used 0.50 h/month; a dishwasher that is used 8.0 h/month; a microwave oven that is used 15 min/day; th

    0
    0
  • (a) How long would it take for a net charge of 2.5 C to pass a location in a wire if it is to carry a steady current of 5.0 mA? (b) If the wire is actually connected directly to the two electrodes of a battery and the battery does 25 J of work on the charge during this time, what is the terminal voltage of the battery?

    0
    0
  • (a) If the resistance of the wire in Exercise 29 cannot vary by more than from its value at ±5.0%, to what operating temperature range should it be restricted? (b) What would be the operating range if the wire were, instead, made of copper?

    0
    0
  • (a) Make an order-of-magnitude estimate of the resistance between the ends of a rubber band. (b) Make an order-of-magnitude estimate of the resistance between the ‘heads’ and ‘tails’ sides of a penny. In each case state what quantities you take as data and the values you measure or estimate for them. (c) WARNING! Do not try th

    0
    365