4.5 Computer quiz

1. For an efficient FFT, the size of the arrays to be transformed must be
   
   1. a multiple of 2
   2. a power of 2
   3. a prime number

2. The linear solution computed for the advection-diffusion equation
   
   1. converges linearly to the physical value
   2. converges quadratically to the physical value
   3. converges faster than any polynomial to the physical value
   4. is exact

3. Compared with Fourier schemes, aliases in finite differences are
   
   1. never a problem (they do not exist)
   2. rarely a problem (short wavelengths numerically damped by spatial operators)
   3. as much a problem

4. Compared with Burger's, the Korteweg-DeVries equation is
   
   1. less sensitive to aliasing
   2. equally sensitive to aliasing
   3. more sensitive to aliasing