EASY SYNTAX BASED MATLAB QUESTIONS
1. We use MATLAB to
solve an equation 2x + 3 = 0. What is the correct function to call and
what is the syntax:
(a) find(‘2 * x +
3’)
(b) roots(‘2 * x +
3’)
(c) solve(‘2 * x +
3’)
(d) solve(‘2 * x + 3’, 0)
2. To calculate the
limit lim x -- 2+ [ (x+3/x+4) ]
the correct MATLAB call
is:
(a) limit((x +
3)/(x – 4), 2, +)
(b) limit((x +
3)/(x – 4)), 2,+
(c) limit((x +
3)/(x – 4), 2, ‘right’)
(d) limit((x + 3)/(x – 4),
2), right
3. To generate a set of
uniformly spaced points for 0 ≤ x ≤ 10 you can write:
(a) x =
linspace(0:10);
(b) x =
linspace(0:0.1:10);
(c) x =
linspace(0, 10, ‘u’);
(d) x = linspace(0, 10);
4. You want to plot two
curves y1 and y2 against x. To plot y1 as a red
lineand y2 as a blue line, the correct command is:
(a) plot(x, y1,
‘r’, x, y2, ‘b’)
(b) plot(x, y1,
‘r’, y2, ‘b’)
(c) plot(x, y1,
“r”, y2, “b”)
(d) plot(x, y1, x, y2),
color(‘r’, ‘b’)
5. You want to plot a
curve as a dashed blue line. The correct command is:
(a) plot(x, y,
‘b–’)
(b) plot(x, y,
‘b–’)
(c) plot(x, y, ‘b’,
‘–’)
6. To add a title to a
graph, the correct command is:
(a) plot(x, y,
‘title–>‘Plot of Sin(x)’)
(b) plot(x, y,
‘Plot of Sin(x)’)
(c) plot(x, y),
title(‘Plot of Sin(x)’)
(d) plot(x, y), Title(‘Plot
of Sin(x)’)
7. To plot a curve as a
red dotted line, the correct command is:
(a) plot(x, y,
‘r’, ‘:’)
(b) plot(x, y,
‘r:’)
(c) plot(x, y, ‘r.’)
8. To create a symbolic
function f(t) = sin(t) the best command to use is:
(a) syms t; f =
sin(t);
(b) syms t; f =
sin(‘t’);
(c) syms t; f =
‘sin(t)’;
(d) a or c
9. To plot a symbolic
function f you call:
(a) quickplot( f )
(b) symplot( f )
(c) ezplot( f )
(d) plot( f,
‘symbolic’)
10. You want to use ezplot
to generate a graph of a function f and its second derivative on the same
graph. The correct command is:
(a) ezplot( f,
diff( f, 2))
(b) subplot(1, 2, 1);
ezplot( f ) subplot(1, 2, 2); ezplot(diff( f, 2))
(c) ezplot( f );
hold on ezplot(diff( f, 2))
(d) ezplot( f );
hold; ezplot(diff( f, 2));
11. You want to use ezplot
to generate a graph of a function f and its second
derivative in
side-by-side plots. The correct command is:
(a) subplot(1, 2, 1);
ezplot( f ) subplot(1, 2, 2); ezplot(diff( f, 2))
(b) ezplot(subplot(1, f
), subplot(2, diff( f, 2))
(c) ezplot( f );
hold on ezplot(diff( f, 2))
12. You have created a
symbolic function f. To display its third derivative, you
can write:
(a) f’’’’
(b) f’’’’ or
diff( f, 3)
(c) derivative( f,
3)
(d) diff( f, 3)
13. The subplot command
(a) Allows you to
generate several plots contained in the same figure.
(b) Allows you to plot
multiple curves on the same graph.
(c) MATLAB does not have
a subplot command.
14. Calling subplot(m,
n, p)
(a) Divides a figure
into an array of plots with m rows and n columns,
putting the current plot
at pane p.
(b) Plots curve n against
m in pane p.
(c) Plots curve p at
location (row, column) = (m, n)
(d) MATLAB does not have
a subplot command.
15. If A is a
column vector, we can create the transpose or row vector B by writing:
(a) B =
transpose(A)
(b) B = A’
(c) B = t(A)
(d) B = trans(A)
16. Suppose that x =
7 and y = –3. The statement x ~= y in MATLAB will generate:
(a) ans = 1
(b) ans = 0
(c) ans = –1
(d) An error
17. To enter the
elements 1 –2 3 7 in a column vector, we type:
(a) [1: –2:3:7]
(b) [1, –2,3,7]
(c) [ 1; –2; 3; 7]
(d) [1 –2 3 7]
18. To compute the
square of a vector f of data, write:
(a) sqr( f )
(b) f. ^ 2
(c) f ^ 2
(d) square( f )
19. To generate the
fourth order Taylor expansion of a function f about the
origin, use:
(a) Taylor( f, 4)
(b) taylor( f, 4)
(c) taylor( f ),
terms(‘4’)
(d) taylor, f, 4
20. A function is
defined as f = a * x ^ 2 – 2. The command solve( f,
a) yields:
(a) 2/a
(b) 2/x
(c) –2/x
(d) An error: rhs must be specified.
21. A variable called y
has one row and 11 columns. If we type size(y) MATLAB returns:
(a) 11
(b) 1 11
(c) 11 1
(d) (1, 11)
22. To implement a for
loop which ranges over 1 ≤ x ≤ 5 in increments of 0.5
the best command is:
(a) for i = 1, 5,
0.5
(b) for i =
1:0.5:5
(c) for loop i =
1, 5, 0.5
(d) loop i =
1:0.5:5 do
23. A function y =
exp(-2*x) is defined numerically
for some data range x. It can be entered using:
(a) y = exp(–x)
* exp(–x)
(b) y = sqr(exp(–x))
(c) y = exp(–x).
* exp(–x)
(d) y =
sqrt(exp(–x))
24. To find the largest
value in a column vector x, type:
(a) max(x)
(b) maximum(x)
(c) largest(x)
25. The labels used by
MATLAB on an x–y plot are specified with:
(a) The labels command.
(b) The xlabel
and ylabel command.
(c) The label command
(d) The text command
26. To specify the
domain and range used in an x–y plot where a <=x <=
b, c <=y
<= d
(a) axis([a b c d ])
(b) axis(a b c d )
(c) axis([a, b,
c, d ])
(d) axis a, b, c, d
27. To plot a log-log
plot, the correct command is:
(a) plot(x, y,
‘log-log’)
(b) loglog(x, y)
(c) log(x, y)
(d) logplot(x, y)
28. When solving a
differential equation using MATLAB, the dsolve command expects the user to
indicate a second derivative of y = f(x) by typing:
(a) y’’
(b) diff(y, 2)
(c) D ^ 2y
(d) D2y
(e) D(Dy)
29. To find a solution
of
Dy/dt+ 2y =
0
The best syntax to use
in MATLAB is:
(a) diff(‘y’ + 2
* y = 0’)
(b) dsolve(‘Dy +
2 * y’)
(c) dsolve(‘Dy +
2 * y = 0’)
(d) diff(Dy + 2y)
30. Who
invented MATLAB and when ?
a.Cleve Moler (1987)
b.Jack Little (1992)
c.Cleve Moler (1985)
d.John Little (1987)
modified sine wave - It's economical one used in TV,ovens etc while where much accuracy is needed the sine wave is used eg. Laptops. It's the sum of two square waves one of which is phase shifted 90 degrees relative to the other.waveform generally has a pause during the polarity reversal.During operation with modified sine wave loads actually has low eficiency and also produces a humming sound.