Concept explainers
(a)
The radius and the mass of the drop used in the experiment.
(a)
Answer to Problem 6P
The radius is
Explanation of Solution
Write the expression for the radius of the oil drop in the Millikan’s experiment.
Here,
The mass of the oil drop is given by,
Here,
The volume of the oil drop is given by,
Use equation (III) in (II),
The average speed of the oil drop is given as,
Conclusion:
Substitute
Substitute
Therefore, the radius is
(b)
The charge on each drop and show that the charge is quantized by considering both the size of each charge and the amount of charge gained when the rise time changes.
(b)
Answer to Problem 6P
It is shown that the charge is quantized by considering both the size of each charge and the amount of charge gained when the rise time changes.
Explanation of Solution
The charge on the droplet is given by,
Here,
The expression for the electric field is given by,
Conclusion:
Using the times given, the various
The corresponding charges can be written as,
Therefore, It is shown that the charge is quantized by considering both the size of each charge and the amount of charge gained when the rise time changes.
(c)
The electronic charge from the data.
(c)
Answer to Problem 6P
The average value is
Explanation of Solution
To find an integer
The amount of charge gained or lost is,
The integers that yield a value of
The average of all values will be
Conclusion:
Therefore, The average value is
Want to see more full solutions like this?
Chapter 4 Solutions
Modern Physics
- In a cathode-ray tube (CRT), an electron travels in a vacuum and enters a region between two "deflection" plates which have equal and opposite charges. The dimensions of each plate are L = 12 cm by d = 5 cm, and the gap between them ish = 2.5 mm. (Note: the diagram is not drawn to scale and the direction of the electric field may not be correct, depending on your randomization.) L During a 0.001 s interval while it is between the plates, the change of the momentum of the electron Ap is kg m/s. What is the electric field between the plates? Hint: remember the Momentum Principle (the relationship between Impulse and change in momentum.) E = N/C What is the charge (both magnitude and sign) of the upper plate? q = Additional Materials I eBookarrow_forwardIn a cathode-ray tube (CRT), an electron travels in a vacuum and enters a region between two "deflection" plates which have equal and opposite charges. The dimensions of each plate are L = 12 cm by d = 5 cm, and the gap between them is h = 2.5 mm. (Note: the diagram is not drawn to scale and the direction of the electric field may not be correct, depending on your randomization.) During a 0.001 s interval while it is between the plates, the change of the momentum of the electron ΔP is < 0, 9.60e-17, 0 > kg m/s.What is the electric field between the plates?arrow_forwardA stream of electrons with a linear number density of 3.10 x 1011 electrons/meter are accelerated from rest by a 62.0-V potential difference applied across two parallel plates. The electrons then pass through an aperture in the high voltage plate and into a current collector where the beam current is measured. Note: The mass of an electron is 9.11 x 10-31 kg. (a) What is the magnitude of the electric field between the plates if they are 2.07 m apart? V/m (b) What is the final velocity of each electron? m/s (c) What is the beam current? Aarrow_forward
- In the Millikan oil drop experiment tiny charged oil droplets generated by a spray are allowed to fall under gravity through a hole in a top electrode, T, towards a bottom electrode B separated from T by 1 cm. When a holding voltage Vh = +0.25V is applied between T and B the droplets are seen to be suspended motionless between the electrodes. What is the specific charge of the droplet q/m? Select one: a. 0.16 C/kg b. 0.392 C/kg с. 2.7 С/kg O d. 1.5 C/kgarrow_forwardWhat is the velocity of a beam of electrons that go undeflected when passing through crossed (perpendicular) electric and magnetic fields of magnitude 1.93×104 V/m and 2.50×10-3T, respectively? me=9.11×10-31kg, e=1.60×10-19 C.arrow_forwardIn a Millikan oil-drop experiment (), a uniform electric field of 1.92 * 10^5 N/C is maintained in the region between two plates separated by 1.50 cm. Find the potential difference between the plates.arrow_forward
- Use Clausius-Mossotti equation to determine the polarizibility of atoms in the air molecules, where the number density of dry air is 2.504×1025 m-3. Assume the result for nitrogen atom and compute the relative displacement of nitrogen nucleus and electronic cloud at a field strength Em= 3×106 V/m.arrow_forwardIn the Millikan oil drop experiment tiny charged oil droplets generated by a spray are allowed to fall under gravity through a hole in a top electrode, T, towards a bottom electrode B separated from T by 1 cm. When a holding voltage Vh = +0.25V is applied between T and B the droplets are seen to be suspended motionless between the electrodes. What is the specific charge of the droplet q/m?arrow_forwardSilver contains 5.8 * 1028 free electrons per cubic meter. At absolute zero, what is the speed of an electron with this energy?arrow_forward
- le (mA) 50 mW/cm2 TU40 mW/cm² 30 mW/cm² (a) Zero (b) 10 mW/cm² (c) 20 mW/cm² (d) 30 mW/cm² 20 mW/cm² 10 mW/cm2 Dark current V₁: (V) Figure 3 A phototransistor with the characteristic shown in Figure 3 has a supply voltage of 20 V and a collector load resistance of 2.5 Kn. Determine the output voltage when the illumination level isarrow_forwardHow much work is done by a gold nucleus placed inside a uniform electric field with a potential difference of 220V? (atomic number of Au = 79) O 2.78 microjoules O 2.78 nanojoules O 2.78 femtojoules O 2.78 picojoulesarrow_forwardA velocity selector consists of two parallel plates with an electric field strength of 1600 N/C. Alpha particles with a velocity of vi = 2100 m/s and v2 = 3300 m/s are to be fired horizontally into the middle of the velocity selector (as shown below). The alpha particles travelling at 3300 m/s are to pass through the velocity selector undeflected, while the slower travelling alpha particles will collide with one of the plates. The effects of gravity can be ignored throughout this question. +, Part A Determine the required strength of the magnetic field nνα ΑΣφ ? B = T Submit Request Answer Part B The required direction of the magnetic field will be O down O up O into the page O out of the page Submit Request Answer Part C An alpha particle is a Helium nucleus, which contains two protons and two neutrons, so it has a mass of 6.68x10-27 kg and a charge of 3.20x10-19 C The slower moving alpha particles will accelerate vertically and collide with the top (negative plate). What will be the…arrow_forward
- Modern PhysicsPhysicsISBN:9781111794378Author:Raymond A. Serway, Clement J. Moses, Curt A. MoyerPublisher:Cengage Learning