 |
1 | |
When two rocket ships A and B move toward each other at uniform speed, it is not possible for the astronauts on either ship to determine whether ship A is moving and ship B is at rest, ship B is moving and ship A is at rest, or both ships are moving. |
|
| | A) | True |
| | B) | False |
|
2 | |
Einstein's second postulate tells us that the velocity of light is always constant. |
|
| | A) | True |
| | B) | False |
|
3 | |
The kinetic energy of a particle traveling at relativistic speeds is equal to the difference between its total energy and its rest mass energy. |
|
| | A) | True |
| | B) | False |
|
4 | |
In the photoelectric effect, a surface with a large work function is likely to produce photoelectrons with higher kinetic energy. |
|
| | A) | True |
| | B) | False |
|
5 | |
de Broglie wavelengths can be calculated only for charged particles such as protons and electrons. |
|
| | A) | True |
| | B) | False |
|
6 | |
The wavelengths from an emission spectrum of an element should not be expected to coincide with the wavelengths determined from an absorption spectrum of that element. |
|
| | A) | True |
| | B) | False |
|
7 | |
The Balmer spectral series in an emission spectrum results from electrons in higher energy levels dropping to the ground state for the hydrogen atom. |
|
| | A) | True |
| | B) | False |
|
8 | |
The stable electron orbits are those that contain an integral number of de Broglie wavelengths. |
|
| | A) | True |
| | B) | False |
|
9 | |
The energy of an electron in the first excited states is 4 times its energy in the ground state. |
|
| | A) | True |
| | B) | False |
|
10 | |
Rutherford's work with the scattering of alpha particles resulted in a nuclear theory of matter. |
|
| | A) | True |
| | B) | False |
|
11 | |
According to the modern theory of relativity, newtonian mechanics is |
|
| | A) | totally incorrect |
| | B) | approximately correct for any velocity |
| | C) | approximately correct for speeds much less than the speed of light |
| | D) | correct for all velocities |
|
12 | |
A clock of mass m and length L records a time interval Δt. If this clock moves with a velocity of 0.6c, which of the following statements is not true? |
|
| | A) | The mass will be larger. |
| | B) | The length will be shorter. |
| | C) | The time interval will be longer. |
| | D) | The time interval will be shorter. |
|
13 | |
The rest mass of a proton is 1.673 x 10-27 kg. The relativistic mass of a proton when its velocity is 0.6c is approximately |
|
| | A) | 1.3 x 10-27 kg |
| | B) | 2.1 x 10-27 kg |
| | C) | 2.6 x 10-27kg |
| | D) | 8.4 x 10-27 kg |
|
14 | |
What is the relativistic mass of an electron whose kinetic energy is 1.0 MeV? |
|
| | A) | 35.6 x 10-31 kg |
| | B) | 29.2 x 10-31 kg |
| | C) | 26.9 x 10-31 kg |
| | D) | 22.5 x 10-31 kg |
|
15 | |
According to the Bohr theory of an atom, an electron may circle the nucleus indefinitely without radiating energy if |
|
| | A) | the radius of its orbit is an integral multiple of the nuclear radius |
| | B) | its orbital path is an integral number of de Broglie wavelengths |
| | C) | its orbit is an integral multiple of its angular momentum |
| | D) | the coulomb force is constant |
|
16 | |
What is the de Broglie wavelength of an electron when it is accelerated through a potential difference of 200 V? |
|
| | A) | 86.8 pm |
| | B) | 62.2 pm |
| | C) | 23.6 pm |
| | D) | 6.92 pm |
|
17 | |
For the hydrogen atom, which of the following energy-level transitions will result in the emission of a photon with the greatest frequency? |
|
| | A) | From n = 2 to n = 1? |
| | B) | From n = 1 to n = 4 |
| | C) | From n = 4 to n = 2 |
| | D) | From n = 3 to n = 1 |
|
18 | |
The threshold frequency for a surface is known to be 5 x 1014 Hz. What is the wavelength of light required to eject a photoelectron having a kinetic energy of
5 eV? |
|
| | A) | 120 nm |
| | B) | 176 nm |
| | C) | 211 nm |
| | D) | 306 nm |
|
19 | |
The energy of the photon emitted when an electron in the hydrogen atom drops from the n = 3 level to the n = 2 level is |
|
| | A) | 10.2 eV |
| | B) | 6.8 eV |
| | C) | 1.89 eV |
| | D) | 1.51 eV |
|
20 | |
For objects traveling past an observer at relativistic speeds, the measurements of length are , the measurements of mass are , and the time intervals on the object are observed to be than when at rest. |
|
|
|
21 | |
The is constant for all observers independent of their state of motion. |
|
|
|
22 | |
The maximum kinetic energy of an ejected photoelectron is equal to the difference between the and . |
|
|
|
23 | |
The lowest energy level in an atom is known as its state. |
|
|
|
24 | |
Electron jumps from higher quantum levels back to the first or lowest quantum level produce the series for the hydrogen atom. Jumps back to the second level produce the series. |
|
|
|
25 | |
If light from an incandescent platinum wire passes through sodium vapor before reaching the slit of a spectroscope, the resulting spectrum lacks the wavelength's characteristic of . Such a spectrum is known as a(n) spectrum. |
|
|
|
26 | |
The is calculated by dividing Planck's constant by the product of the mass and velocity of a particle. |
|
|
|
27 | |
The minimum energy required to eject a photoelectron from a surface is known as the . |
|
|