Objective Questions
-------------------
.. A mininum of 8 questions here (along with answers)
1. What will be output of the following code snippet,
::
from math import sqrt
def sqrt(i):
return i
print sqrt(49)
a. 7.0
#. 7
#. 49
#. 49.0
#. Error
Answer: 49
2. What will be the output of the following code snippet,
::
import math
def sqrt(i):
x = math.sqrt(i)
if int(x) == x:
return int(x)
else:
return x
print math.sqrt(50), sqrt(50), math.sqrt(49), sqrt(49)
a. 7.0710678118654755 7 7 7
#. 7.0710678118654755 7 7.0 7
#. 7 7 7 7
#. 7.0710678118654755 7.0710678118654755 7.0 7
Answer: 7.0710678118654755, 7.0710678118654755, 7.0, 7
3. ``from math import *`` and ``import math`` does the same,
a. True
#. False
Answer: False
4. Which among these libraries is part of python standard library,
a. Mayavi
#. scipy
#. matplotlib
#. urllib2
Answer: urllib2
5. ``pylab.plot(x,sin(x))`` can be used in a script with ``from pylab
import *``
a. True
#. False
Answer: False
6. Which among this is correct,
a. from scipy import plot
#. from numpy import plot
#. from matplotlib import plot
#. from pylab import plot
#. None of the above
Answer: from pylab import plot
7. Functions ``xlim()`` and ``ylim()`` can be imported to the current
name-space as,
a. from pylab import xlim, ylim
#. import pylab
#. from scipy import xlim, ylim
#. import scipy
Answer: from pylab import xlim, ylim
8. ``scipy.linspace(-5*scipy.pi, 5*scipy.pi, 500)``
a. creates an array of 500 equally spaced elements from -5*scipy.pi
to 5*scipy.pi(excluded)
#. creates an array of 500 equally spaced elements from
-5*scipy.pi(excluded) to 5*scipy.pi(included)
#. creates an array of 500 equally spaced elements from -5*scipy.pi
to 5*scipy.pi, both end points included
#. created an array of 500 equally spaced elements from -5*scipy.pi
to 5*scipy.pi, both end points excluded.
#. None of the above
Answer: creates an array of 500 equally spaced elements from
-5*scipy.pi to 5*scipy.pi, both end points included
Larger Questions
----------------
.. A minimum of 2 questions here (along with answers)
1. Write a python script to plot a red colour tan plot between -pi to
pi, with x limits from -pi to pi. Label the figure appropriately
and with a legend 'tan(x)' and title 'tangent plot'. Label the axes
x as 'x' and y as 'tan(x)'. Make sure the script can be executed as
a python script.
2. Write a python script to plot a parabola of the form y^2=4ax with a
= 0.5(a is the directrix), plot the line in green color add the
legend as 'y^2=4ax' and title as 'parabola'. For x from -20 to 20
with 100 equidistant points. Make sure the script can be executed
as a python script. [`Hint`: Use parametric equations]