BackA particle with charge nC is in a uniform electric field directed to the left. The charge is released from rest and moves to the left; after it has moved cm, its kinetic energy is J. What is the work done by the electric force?
A parallel-plate capacitor with a 1.0 mm plate separation is charged to 75 V. With what kinetic energy, in eV, must a proton be launched from the negative plate if it is just barely able to reach the positive plate?
A 1.5 V battery provides 0.50 A of current. How much work does the charge escalator do to lift 1.0 C of charge?
Light from the sun allows a solar cell to move electrons from the positive to the negative terminal, doing 2.4×10−19 J of work per electron. What is the emf of this solar cell?
A point charge is moved by the electric force from point a, which is at electric potential , to point d, which is at electric potential . What is the work done by the electric force during this process?
An electron moves from point A to point B. The potential difference between these two points is 100 V. What is
a. the point of higher potential?
b. the work done on the electron?
c. the final speed of the electron if its initial speed is zero?
A proton's speed as it passes point 1 is 50,000 m/s. It follows the trajectory shown in FIGURE P25.43. What is the proton's speed at point 2?
The luminous efficiency of a lightbulb is the ratio of luminous flux to electric power input.
(a) What is the luminous efficiency of a 100-W, 1600-lm bulb?
(b) How many 40-W, 60-lm/W fluorescent lamps would be needed to provide an illuminance of 250 lm/m² on a factory floor of area 22 m x 30 m? Assume the lights are 10 m above the floor and that half their flux reaches the floor.
An arrangement of source charges produces the electric potential V=5000x2 along the x-axis, where V is in volts and x is in meters. What is the maximum speed of a 1.0 g, 10 nC charged particle that moves in this potential with turning points at ±8.0 cm?
(II) A + 25 μC point charge is placed 6.0 cm from an identical +25 μC point charge. How much work would be required by an external force to move a +0.15 μC test charge from a point midway between them to a point 1.0 cm closer to either of the charges?
In an older television tube (CRT), electrons are accelerated by thousands of volts through a vacuum. If such a television set is laid on its back, would electrons be able to move upward against the force of gravity? What potential difference, acting over a distance of 2.4 cm, would be needed to balance the downward force of gravity so that an electron would remain stationary? Assume that the electric field is uniform.
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