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

- 4.7 x 10
- 8.4 x 10
- 4.8 x 10
- 8.7 x 10
^{19}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?

- 1.89 eV
- 2.04 eV
- 2.25 eV
- 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?

- Initial temperatures
- Specific Heat values
- Melting points
- Heats of fusion

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

- Electrons
- Neutrons
- Photons
- 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?

- Less than .05 ampere
- Greater than .05 ampere
- 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?

- 4.6 x 10
- 4.6 x 10
- 4.7 x 10
- 4.7 x 10
^{-18}

##### 7. Which particle cannot be accelerated by a cyclotron?

- Proton
- Neutron
- Electron
- 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?

- 3 minutes
- 4 minutes
- 5 minutes
- 6 minutes

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

- Have a relatively low atomic mass
- Can be easily accelerated
- Have a very high kinetic energy
- 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?

- 1.0 x 10
- 1.0 x 10
- 2.0 x 10
- 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 Electron
- 1 Proton
- 3 Electrons
- 3 Protons

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

- Loss of 10.20 eV
- Gain of 10.20 eV
- Loss of 11.70 eV
- Gain of 11.70 eV

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

- Energy, only
- Momentum, only
- Energy and Momentum
- Neither Energy or Momentum

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

- Electrons are emitted at a lower rate.
- Electrons are emitted at a higher rate.
- Protons are emitted at a lower rate.
- Protons are emitted at a higher rate.