# Physics and Astronomy Labs/Upcoming Test (a)

## For the next Astronomy test on March 18, 2015

Questions not on this list will be on the next astronomy test

## March 18 lab portion

1 If an electron's charge equals 2 in some units, and if r is the number of electrons per second, then the the current, I, equals

 I=2r I=(1/2)r I=4r I=r

2 If an electron's charge equals 1/2 in some units, and if r is the number of electrons per second, then the the current, I, equals

 I=(1/2)r I=2r I=4r I=r

3 In the gravitational analogy to electrostatics and electricity, what is the analog to charge? (Here, m is mass, h is height, and g is gravitational acceleration. Also, the formula for gravitational potential energy is mgh)

 m mg mgh gh

4 If the breakdown field for air is typically 60kv/inch (i.e. 60,000 volts per inch). What does that say about the voltage associated with a two inch spark?

 120 kV 60 kV 30 kV 240 kV

5 If the breakdown field for air is typically 60kv/inch (i.e. 60,000 volts per inch). What does that say about the electric field associated with a two inch spark?

 120 kV/inch 60 kV/inch 30 kV/inch 240 kV/inch

## partition for testmakers

questions under constructin that will NOT be on the next test

## group 1

1 The units for qV=energy

 energy Joule/Coloumb Joules Coloumb

2 If an electron's charge equals 2 in some units, and if r is the number of electrons per second, then the the current, I, equals

 I=2r I=(1/2)r I=4r I=r

3 If an electron's charge equals 1/2 in some units, and if r is the number of electrons per second, then the the current, I, equals

 I=(1/2)r I=2r I=4r I=r

4 In the gravitational analogy to electrostatics and electricity, what is the analog to charge? (Here, m is mass, h is height, and g is gravitational acceleration. Also, the formula for gravitational potential energy is mgh)

 m mg mgh gh

## Group 2

1 Voltage is expressed as?

 energy/q q/energy I/gh gh/q

2 Is current equal to the number of electrons per second flowing through a wire?

 only in units where the charge of the electron equals one yes no only in units where the charge of the electron equals the potential energy of a mouse

3 In the gravitational analogy to electrostatics and electricity, what is analogous to voltage? (Here, m is mass, h is height, and g is gravitational acceleration.

 m mg mgh gh

4 question?

 yes wrong wrong wrong

5 question?

 yes wrong wrong wrong