If an electron has a wavelength of 0.123 nm, what is its kinetic ...

[kodithompson]

If an electron has a wavelength of 0.123 nm, what is its kinetic energy, in electron-volts? This energy is not in the relativistic region. (melectron = 9.11  10-31 kg, 1 eV = 1.60  10-19 J, h = 6.626  10-34 J  s)
 
  A) 19.8 eV
  B) 60.2 eV
  C) 80.4 eV
  D) 99.5 eV
  E) 124 eV

Question 2

An ideal transformer with 120 turns in its secondary supplies 12 V at 220 mA to a toy train. The primary is connected across a 120-V wall outlet.
 
  (a) How many turns are in the primary?
  (b) What is the primary current?
  (c) What power is delivered by the wall outlet?

[kaillie]

Answer to Question 1

D

Answer to Question 2

(a) 1200 (b) 22 Ma (c) 2.6 W

[kodithompson]

Great answer, keep it coming

[matt95]

Thanks for the timely response, appreciate it