MATLAB Practice Test 1

1. What does the Workspace show?

Attributes of variables, script files, functions from command window

Attributes of variables from command window

Attributes of variables, script files from command window

Attributes of variables, functions from command window

2. The uniform distribution can range from -infinity to 0 or 0 to Infinity but not from -infinity to infinity.

False

True

3. What is the conclusion from the following code?

 >>whos
 Name     Size         Bytes    Class     Attributes
 ans      1x1            8      double              
 ap       1x1          112  	sym              
 c        1x2            4      char
 p        1x1            8      double

The value of each variable is 0

The function ‘whos’ doesn’t show the values of the variables being used

The function ‘who’ is more effective than ‘whos’

Nothing can be concluded

4. Round each value in a duration array to the nearest number of seconds greater than or equal to that value.

t = hours(8) + minutes(29:31) + seconds(1.23);
t.Format = 'hh:mm:ss.SS'
t = 08:29:01.23   08:30:01.23   08:31:01.23
Y1 = ceil(t)
Y2 = ceil(t,'hours')

     Y1 =  08:29:01.23   08:30:01.23   08:31:01.23
     Y2 =  08:29:01.23   08:30:01.23   08:31:01.23

     Y1 =  008:29:01.23   08:30:01.23   08:31:01.23
     Y2 =  09:00:00.00   09:00:00.00   09:00:00.00

     Y1 =  08:29:02.00   08:30:02.00   08:31:02.00 
     Y2 =  08:29:01.23   08:30:01.23   08:31:01.23

     Y1 =  08:29:02.00   08:30:02.00   08:31:02.00 
     Y2 =  09:00:00.00   09:00:00.00   09:00:00.00

5. What will be the output for the below block of code?

	P=[1 3 2]; r=roots(P);

   r = -2
       -1

r=[-2 -1]

There is an error in the code

r=[-2,-2]

6. Find the error in the following code?

Predicted output: (b + (b² - 4*a*c)^(1/2))/(2*a)
     (b - (b² - 4*a*c)^(1/2))/(2*a)
Code: solve (b*x² + c*x + a == 0)
Present output: -(c + (c² - 4*a*b)^(1/2))/(2*b)
 		-(c - (c² - 4*a*b)^(1/2))/(2*b)

solve(a*x² - b*x + c == 0)

solve(a*x² + b*x + c == 0)

Predicted output is same as present output after math magic

vpa(solve(a*x² - b*x + c == 0))

7. What would be the output of the following code (in editor window)?

X = [1 2 3;4 5 6;7 8 9];
Y = [9 8 7;6 5 4;3 2 1];
R = rem(X,Y)

   R = 1     2     3
       4     1     2
       1     1     0

   R = 1     2     3
       4     0     2
       1     0     0

   R = 1     2     3
       3     0     2
       1     0     0

   R = 1     2     1
       4     0     9
       1     0     0

8. What would be the output of the following code (in editor window)?

A = [1 0 2]	;	b = [3 0 7]	;	c=a.*b;

[3 0 14]

[2 0 21]

[7 0 3]

[14 0 3]

9. Conversion Function int16 uses_________ range of value?

-2⁷ to 2⁷-1

-2³¹ to 2³¹-1

-2¹⁵ to 2¹⁵-1

0 to 2¹⁶-1

10. Compute 24 modulo 5.

b = mod(24,5)

b =5

b =6

b =4

b = 3