Class 4 Computer Chapter 5 LOG ON TO LOGICS ( Complete Solution )

 Class 4 Computer 

Chapter 5  

LOG ON TO LOGICS   

( Complete Solution )

1. Write 'T' for True or 'F' for false for the following :-

a)  Turtle is used as a pencil for drawing. T

b) Primitive RT moves the 'Turtle' in its right direction.  T

c) The Turtle looks similar to triangle.   T

d) ' , ' LOGO operator is used for division.    F

e) 'PRODUCT' command is used for multiplication.   T

2. Match the following:-

a) ROUND   ( c ) displays the absolute (positive) value

b) INT          ( a ) converts any decimal numbers to its nearest integer.

c) ABS          ( d ) displays the number of elements in its input. 

d) COUNT   ( b ) extracts the integer portion of any fractional number.

3. Write the LOGO operators for the following functions:

a) Addition               +                  

b) Subtraction          — 

c) Multiplication     *    

d) Division                  /  

4. Priyanshu is trying to draw a semi circle by typing REPEAT 240 [FD 1 RT 1 primitive. But his teacher feels that it will not be a perfect semi circle and tells him to try again.  Rectify the error in his program.

Ans.-  To draw semi-circle you can write the following primitive : 

REPEAT180 [FD1RT1]

5. With the help of LOGO Primitives, find the solution of the following:

(a) How much is twelve times six decreased by six times twelve?

Ans.- SHOW6*12-12*6↲               Output:0

           

(b) Suppose your home is 5 km away from the school and your friend's house is 7 km away from the school in the opposite direction from yours. How long is the distance of your house from your friend's house? Find the answer using LOGO Primitives.

Ans.- SHOW(SUM5 7)↲                Output:12

          

(c) Ankit buys 2 dozen bananas from a super market store. He wants to distribute the bananas among his four children. Use LOGO operator to find how many bananas can be distributed to each child?

Ans.- SHOW24/4↲                 Output:6

          

6. Explain about 'MSWLogo Turtle'.

Ans.- Turtle is the cursor of LOGO that moves on the screen as per the commands typed or written in the input box.            

7. What is 'Input Box' in MSWLogo?

Ans.- Input Box generally appears towards the bottom side of screen.  It is the text area. It accepts commands entered by the user through the keyboard. As the user types a command, it is shown in the 'Input Box'.

8) Complete the following:-

a) I am also known as 'Graphic Screen' in MSWLogo.

Ans- MAIN SCREEN 

b) I am used to set the thickness of the line that turtle draws.

Ans- PEN SIZE 

c) I am the button that is used to open 'Editor' Window in  MSWLogo.

Ans- EDALL

d) I am the command used to bring the turtle to its starting position.

ANS.- HOME

9) Write the purpose of following commands

a)  CS:-  CS primitive is used to clear the graphic area. 

b) CT:-  CT primitive is used to clear the text. 

c) FD:- FD primitive is used to move the turtle ahead (forward) by given number of steps.

d) PE:-  PE primitive makes the turtle like an eraser so that it can erase lines while moving.

10) Write the difference between following commands:

a) HT and ST 

Ans.- HT primitives is used to make the turtle invisible but ST primitive is used to make the turtle visible. 

b) PU and PD

Ans.- PU primitive is used to move the turtle without drawing any line but PD primitive is used to let the turtle draw line with its movement.