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Correct CHOICE is (b) False

Easy explanation: Clear all REMOVES VARIABLES from the workspace. It does not remove graphs.

The correct choice is (a) True

Explanation: The integrator CIRCUIT integrates the input waveform within a given time limit. Hence, to find the response of the integrator, we can USE the quad() COMMAND since it COMPUTES definite integration only. But if we WANT to find the steady state response, we cannot do it using quad() since it does not compute for an infinite limit. Hence, we have to use the int() command.

Correct ANSWER is (a) abs(sumsqr())

For explanation: The command sumsqr () finds the SUM of squares of finite VARIABLES in a series. If we give sumsqr(abs()), it will convert all the values in the series to absolute values so we won’t GET the true sum of the series. sumsqr()will only give the sum of all the values in the series.

Right choice is (a) symsum

Easiest explanation: The in-built command to find the SUMMATION of a series generated due to a CHARACTER is symsum. SINCE our function USES symbolic characters, we NEED to express our function within the symsum command to get the summation.

Right option is (a) Unsorted

To elaborate: The eig(a,’matrix’) COMMAND will RETURN the EIGEN values of the matrix ‘a’ in a matrix form. But, it will give it in an unsorted manner- the elements will be PLACED on the PRINCIPAL diagonal. To sort them, we need to use the sort command- this will sort the columns in ascending order.

Correct choice is (c) Can be modelled

For explanation I WOULD SAY: We have 8 different Ordinary differential equations solvers in MATLAB. They take the initial values, if at all present, into account while solving the Differential equation of interest. Hence, systems which follow a differential equation can be modelled and OBSERVED using MATLAB.

Right ANSWER is (B) False

To elaborate: EVEN only 1 element can be PUT into the memory which has been already allocated by the spalloc COMMAND. Hence, the above statement is false.

Correct choice is (a) spalloc

The best explanation: The spalloc COMMAND is used to allocate memory for a sparse MATRIX. The REST of the commands are INCORRECT.

Correct answer is (B) mean()

EXPLANATION: The mean() command is an INBUILT command which can be used to compute the mean of n no. of values in a SERIES. meanabs() will TAKE the sum of absolute values in the series while sumabs() only computes the sum of absolute values in the series.

The correct CHOICE is (b) nonzeros

The EXPLANATION: The non-zeros COMMAND is used to get the non-zero elements present in the sparse MATRIX. The rest of the OPTIONS are not defined in MATLAB.

The correct option is (a) Z

Best EXPLANATION: The default PARAMETER for the given COMMAND is z. This is a pre-defined command in MATLAB and uses the basic definition of the Z-transform to EVALUATE the result.

The CORRECT CHOICE is (b) False

Easy explanation: There are total 8 ODE solvers in MATLAB. They are INBUILT in MATLAB and each can be used for solving ODEs with initial values. They ALSO provide varying accuracy.

Correct answer is (b) At least ONE INDEPENDENT variable

For explanation: Derivatives are calculated with RESPECT to a CHANGE in an independent variable. Hence for deriving a derivative- the equation should have at least one independent variable so that we can FIND the derivative with respect to a change in that independent variable.

The CORRECT choice is (a) Check waveforms after superpostion

Explanation: Since we have the transfer function of a system, we need to apply SUPERPOSITION and compare the waveforms GENERATED after applying the method of superposition. Rouche’s THEOREM is for a system of equations represented by matrices and it is the method of comparing ranks.

Right answer is (a) A system which follows homogeneity and additivity

Explanation: A system which follows homogeneity and additivity is CALLED linear system. This comes from the definition of superposition and here is the proof:

Taking a system with which PRODUCES Y1(t) as output for an INPUT x1(t) and an output y2(t) for an input x2(t),

HOMOGENITY: For input ax1(t), output should be ay1(t) and for input bx2(t), output should be by2(t).

ADDITIVITY: For a input of sum of x1(t) and x2(t), output should be the sum of a y1(t) and y2(t), i.e. the sum of individual response

Finally, if for an input of the sum of ax1(t) and bx2(t), if we GET the output as sum of ay1(t) and by2(t) the system is both homogeneous and additive. This is similar to the superposition principle. No the system is linear.

The correct choice is (c) echo on

For EXPLANATION I WOULD say: A user-defined FUNCTION is a function file. The commands ‘HELP’ and ‘look for’ will only return the nature of in-built function. If the function file has ‘echo on’, it will display the expressions in the function file while executing.This is because function files, though they are different from script files, are inherently M-files.

The correct choice is (d) Depends on the number of variables

Explanation: If we have a very big expression relating a VARIABLE y with any no. of variables x1,x2…xn we can put the entire expression on the right HAND side within a function and reduce the expression to

 y=func(x1,x2,x3…xn)

This CONTAINS two expressions only. The function, ‘func’, may contain a SET of 10000 statements. But we have simplified the expression to demonstrate a mathematical relation between y and all the other variables of the right-hand side, provided we are sure about the NATURE of the function ‘func’.

Right answer is (a) QUAD(‘[]’)

Explanation: The inline function, being a non-linear function and saved as an inline class, will be given as a string argument to the quad() command. Due to its non-linear nature, it has to be PLACED like a MATRIX. quad(‘’) will only take the function but the function is non-linear so it will show an ERROR. quad([‘’]) is wrong because the ‘’ should COMPRISE the entire function, hence it should be outside []. quad([]) is syntactically wrong.

Correct choice is (b) syms n;limit(n-1,n,3,’right’)

Easiest EXPLANATION: We have to GIVE our symbolic argument before our limit COMMAND. HENCE, syms n;limit(n-1,n,3,’right’) has the right order, and not syms n;limit(n-1,3,n,’right’). syms n;limit(n-1,n,3,’right’) is not same as limit(n-1,n,3) since there we are calculating the value of the function at the limiting value, 3, but we need to find it at the right-hand side of the limiting value- plus, limit(n-1,n,3) does not declare n as symbolic- this will give an error. syms n;limit(n-1,3,’right’) will give an error since the symbolic argument is not provided into the command.

Right option is (b) Different

Explanation: The output for int(x^2,1,3) will be 26/3. The output for quad(‘x. ^2’,1,3) is 8.6667. Hence we find that each output will be different. The int command will RETURN a fractional form while the quad command will return a decimal form up to 4 PLACES of decimal, ROUNDED up to the 4^th decimal place.

Output:

For int(x^2,1,3): 26/3

For quad(‘x. ^2’,1,3) : 8.6667

Correct option is (a) Yes

Easiest explanation: We can do vector integration in MATLAB. We simply NEED to integrate the co-efficient of the vector in a certain direction with respect to an independent VARIABLE. HENCEFORTH, we can do many applications of Vector Calculus.

Right choice is (a) 1

To ELABORATE: Unlike C, the starting address of an array in MATLAB is 1. Hence if we declare an array named arr and TYPE arr(0), we will get an ERROR. The FIRST entry to the array will have the index 1.

Correct ANSWER is (a) Same as a sparse MATRIX

To elaborate: The spones command also CREATES a sparse matrix. Hence, the NEWLY generated matrix will have the same size as that of a sparse matrix.

Correct option is (d) Overlap add METHOD

To explain I would say: The overlap add method is used by the fftfilt command to generate the filtered sequence. This command is only ALLOWED for FIR FILTERS.

Right answer is (d) N-point symmetric blackmann window

The best I can EXPLAIN: Unless mentioned, the default type of blackmann window GENERATED by the blackmann() COMMAND is a symmetric ONE. It is an N-point symmetric blackmann window and hence the REST of the options are incorrect.

Correct CHOICE is (C) Inf

For explanation: The sum function is INBUILT in MATLAB. It has been developed so that if the summation of our given series becomes INFINITE, it will return a Inf as an output.

Right answer is (d) does not exist

The best explanation: It is not POSSIBLE that the derivative of a FUNCTION can never be 0. This is because there will always be a case where the derivative of the function becomes 0 for a certain value of X. This value of x can be real or imaginary.

Correct choice is (B) False

To elaborate: If we give NEGATIVE limiting values to logarithmic functions, they will return imaginary numbers. These can be treated as SOLUTIONS to such problems. MATLAB is a very powerful COMPUTING TOOL that can be used to solve such problems.

The CORRECT choice is (a) True

Easy explanation: If a function is differentiable, it should be continuous in the DOMAIN where it is differentiable. This is because if the function is not continuous, within a range, it cannot be differentiated within that range.

Correct option is (b) False

Best explanation: The MODULUS of z, z conjugate and -z are EQUAL. The MAGNITUDE of the modulus is ALWAYS a positive number. It is independent of the positive or negative NATURE of the real and imaginary parts of the complex number.

Correct CHOICE is (a) True

To explain I would say: The CLEAR command removes EVERY VARIABLE from the workspace. If we only mention the variable name, it will delete only that variable from the workspace and not the ENTIRE workspace will be cleared.