1. What is the net static electric charge on a metal sphere having an excess of +3 elementary charges?

1. 4.7 x 10
2. 8.4 x 10
3. 4.8 x 10
4. 8.7 x 10¹⁹ C

2. A hydrogen atom could have an electron energy level transition from n=2 to n=3 by absorbing a photon having an energy of?

1. 1.89 eV
2. 2.04 eV
3. 2.25 eV
4. 2.87 eV

3. Two solid metal blocks are placed in an insulated container. If there is a net flow of heat between the blocks, they must have different?

1. Initial temperatures
2. Specific Heat values
3. Melting points
4. Heats of fusion

4. A (P type) semiconductor is formed by adding impurities, which provide extra ____.

1. Electrons
2. Neutrons
3. Photons
4. Holes

5. A student measures a current of .05 ampere through a P type semiconductor. If the battery connections are reversed, the current through the semiconductor will be?

1. Less than .05 ampere
2. Greater than .05 ampere
3. The same

6. What is the approximate bind energy of a helium nucleus that has a mass defect of 5.2 x 10^-29 kilogram?

1. 4.6 x 10
2. 4.6 x 10
3. 4.7 x 10
4. 4.7 x 10^-18

7. Which particle cannot be accelerated by a cyclotron?

1. Proton
2. Neutron
3. Electron
4. Alpha particle

8. A 96 gram sample of a radioactive nuclide is placed in a container. After 12 minutes only 6 grams of the sample has not yet decayed. What is the half life of the nuclide?

1. 3 minutes
2. 4 minutes
3. 5 minutes
4. 6 minutes

9. The principal reason for using neutrons to bombard a nucleus is that neutrons?

1. Have a relatively low atomic mass
2. Can be easily accelerated
3. Have a very high kinetic energy
4. Are not repelled by the nucleus

10. What is the magnitude of the gravitational force between an electron and a proton separated by a distance of 1.0 x 10^-10 meter?

1. 1.0 x 10
2. 1.0 x 10
3. 2.0 x 10
4. 3.05 x 10^-47 N

11. A sphere has a net excess charge of -4.8 x 10^-19 coulomb. The sphere must have an excess of ______.

1. 1 Electron
2. 1 Proton
3. 3 Electrons
4. 3 Protons

12. An excited hydrogen atom returns to its ground state. A possible energy change for the atom is?

1. Loss of 10.20 eV
2. Gain of 10.20 eV
3. Loss of 11.70 eV
4. Gain of 11.70 eV

13. During a collision between a proton and an electron there is conservation of _____.

1. Energy, only
2. Momentum, only
3. Energy and Momentum
4. Neither Energy or Momentum

14. As the temperature of a surface increases, how does the rate of thermionic emission change?

1. Electrons are emitted at a lower rate.
2. Electrons are emitted at a higher rate.
3. Protons are emitted at a lower rate.
4. Protons are emitted at a higher rate.

Answer Key

1. C
2. A
3. A
4. D
5. B
6. C
7. B
8. A
9. D
10. B
11. C
12. A
13. C
14. B