Concept explainers
CALC A vacuum tube diode consists of concentric cylindrical electrodes, the negative cathode and the positive anode. Because of the accumulation of charge near the cathode, the electric potential between the electrodes is given by
where x is the distance from the cathode and C is a constant, characteristic of a particular diode and operating conditions. Assume that the distance between the cathode and anode is 13.0 mm and the potential difference between electrodes is 240 V. (a) Determine the value of C. (b) Obtain a formula for the electric field between the electrodes as a function of x. (c) Determine the force on an electron when the electron is halfway between the electrodes.
Want to see the full answer?
Check out a sample textbook solutionChapter 23 Solutions
University Physics with Modern Physics (14th Edition)
Additional Science Textbook Solutions
The Cosmic Perspective
University Physics Volume 1
Introduction to Electrodynamics
Conceptual Physics (12th Edition)
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
- Two point charges, q1 = 2.0 C and q2 = 2.0 C, are placed on the x axis at x = 1.0 m and x = 1.0 m, respectively (Fig. P26.24). a. What are the electric potentials at the points P (0, 1.0 m) and R (2.0 m, 0)? b. Find the work done in moving a 1.0-C charge from P to R along a straight line joining the two points. c. Is there any path along which the work done in moving the charge from P to R is less than the value from part (b)? Explain.arrow_forwardAn electron moving parallel to the x axis has an initial speed of 3.70 106 m/s at the origin. Its speed is reduced to 1.40 105 m/s at the point x = 2.00 cm. (a) Calculate the electric potential difference between the origin and that point. (b) Which point is at the higher potential?arrow_forwardAn electric potential exists in a region of space such that V = 8x4 2y2 + 9z3 and V is in units of volts, when x, y, and z are in meters. a. Find an expression for the electric field as a function of position. b. What is the electric field at (2.0 m, 4.5 m, 2.0 m)?arrow_forward
- In a certain region of space, a uniform electric field is in the x direction. A particle with negative charge is carried from x = 20.0 cm to x = 60.0 cm. (i) Does the electric potential energy of the charge-field system (a) increase, (b) remain constant, (c) decrease, or (d) change unpredictably? (ii) Has the particle moved to a position where the electric potential is (a) higher than before, (b) unchanged, (c) lower than before, or (d) unpredictable?arrow_forwardA filament running along the x axis from the origin to x = 80.0 cm carries electric charge with uniform density. At the point P with coordinates (x = 80.0 cm, y = 80.0 cm), this filament creates electric potential 100 V. Now we add another filament along the y axis, running from the origin to y = 80.0 cm, carrying the same amount of charge with the same uniform density. At the same point P, is the electric potential created by the pair of filaments (a) greater than 200 V, (b) 200 V, (c) 100 V, (d) between 0 and 200 V, or (e) 0?arrow_forwardAn infinite number of charges with q = 2.0 C are placed along the x axis at x = 1.0 m, x = 2.0 m, x = 4.0 m, x = 8.0 m, and so on, as shown in Figure P26.78. Determine the electric potential at the point x = 0 due to this set of charges. Hint: Use the mathematical formula for a geometric series, 1+r+r2+r3+r4+=11r FIGURE P26.78arrow_forward
- At a certain distance from a charged particle, the magnitude of the electric field is 500 V/m and the electric potential is 3.00 kV. (a) What is the distance to the particle? (b) What is the magnitude of the charge?arrow_forwardThree particles with equal positive charges q are at the corners of an equilateral triangle of side a as shown in Figure P20.10. (a) At what point, if any, in the plane of the particles is the electric potential zero? (b) What is the electric potential at the position of one of the particles due to the other two particles in the triangle? Figure P20.10arrow_forwardA Consider a thin rod of total charge Q and length L (Fig. P26.43). Show that the electric potential at point P, a distance x from the end of the rod, is given by V(x)=kQLln(x+Lx) FIGURE P26.43 Problems 43 and 54.arrow_forward
- (a) Find the electric potential difference Ve required to stop an electron (called a stopping potential) moving with an initial speed of 2.85 107 m/s. (b) Would a proton traveling at the same speed require a greater or lesser magnitude of electric potential difference? Explain. (c) Find a symbolic expression for the ratio of the proton stopping potential and the electron stopping potential. Vp/Ve.arrow_forward(a) Calculate the electric potential 0.250 cm from ail electron, (b) What is the electric potential difference between two points that are 0.250 cm and 0.750 cm from an electron? (c) How would the answers change if the electron were replaced with a proton?arrow_forwardA metallic sphere of radius 2.0 cm is charged with +5.0C charge, which spreads on the surface of the sphere uniformly. The metallic sphere stands on an insulated stand and is surrounded by a larger metallic spherical shell, of inner radius 5.0 cm and outer radius 6.0 cm. Now, a charge of 5.0C is placed on the inside of the spherical shell, which spreads out uniformly on the inside surface of the shell. If potential is zero at infinity, what is the potential of (a) the spherical shell, (b) the sphere, (c) the space between the two, (d) inside the sphere, and (e) outside the shell?arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning