## Choose the correct option

#### Question 1

Which of the following is not a valid numeric constant?

- -325
- -99.99
- $24
- 0.00025

**Answer**

$24

**Reason** — Numeric constants can only consist of numbers (0 - 9) and decimal sign (.). They cannot have a $ sign.

#### Question 2

Which of the following is a valid string variable?

- AB$
- AB$$
- $AB$
- $$AB

**Answer**

AB$

**Reason** — String variables must end with a $ sign.

#### Question 3

Which of the following is a valid string constant?

- Computer Science
- 'Computer Science'
- "Year - 2022"
- !!Computer!!

**Answer**

"Year - 2022"

**Reason** — String constants are always enclosed in double quotes ("").

#### Question 4

Which of the following statements is correct for numeric variables?

- They cannot store numbers.
- They are used for mathematical operations.
- They begin with a dollar sign.
- They can store string constant.

**Answer**

They are used for mathematical operations.

**Reason** — Numeric variables store numbers so they are used for mathematical operations.

#### Question 5

Which of the following statements is correct in QBASIC?

- Negative numbers cannot be assigned to a variable.
- Only positive numbers can be assigned to a variable.
- Numeric constant can only be assigned to numeric variables.
- Numeric variables are assigned to numeric constants.

**Answer**

Numeric constant can only be assigned to numeric variables.

**Reason** — Numeric variables are used to store numeric values or numeric constants.

## Fill in the blanks

#### Question 1

Alphanumeric variables always end with a * dollar ($)* sign.

#### Question 2

* Numeric* constants include only numbers.

#### Question 3

The maximum length of a variable is * 12*.

#### Question 4

* Alphanumeric* constants are always enclosed in double quotes.

#### Question 5

Variables always begin with * alphabets*.

#### Question 6

A comma is not allowed while writing * numeric* constants.

## State True or False

#### Question 1

A45 is a valid numeric variable.**True**

#### Question 2

A+B is not a valid alphanumeric variable.**True**

#### Question 3

Special characters are used in variables.**False**

#### Question 4

Numeric constants are stored in numeric variables.**True**

#### Question 5

0.5495 is a valid numeric constant.**True**

#### Question 6

Decimals are not allowed in numeric constants.**False**

## Match the following

#### Question 1

Sl. No. | Column 1 | Column 2 |
---|---|---|

1 | Numeric constants | Alphanumeric constants |

2 | Alphanumeric variables represent | are always enclosed in " " |

3 | Alphanumeric constants | must begin with an alphabet |

4 | A variable | String variables |

5 | Alphanumeric variables are called | can take part in mathematical operations |

**Answer**

Sl. No. | Column 1 | Column 2 |
---|---|---|

1 | Numeric constants | can take part in mathematical operations |

2 | Alphanumeric variables represent | Alphanumeric constants |

3 | Alphanumeric constants | are always enclosed in " " |

4 | A variable | must begin with an alphabet |

5 | Alphanumeric variables are called | String variables |

## Name the following

#### Question 1

Two types of variables

**Answer**

- Numeric variables
- Alphanumeric variables

#### Question 2

Two types of constants

**Answer**

- Numeric constants
- Alphanumeric constants

## Correct the following statements

#### Question 1

B$ = WORLD CUP 2007

**Answer**

B$ = "WORLD CUP 2007"

#### Question 2

"DELHI PUBLIC SCHOOL" = D$

**Answer**

D$ = "DELHI PUBLIC SCHOOL"

#### Question 3

$$A = "ARYA PUBLISHING COMPANY"

**Answer**

A$ = "ARYA PUBLISHING COMPANY"

#### Question 4

P$ = (A + B)^{2}

**Answer**

P = (A + B) ^ 2

#### Question 5

4B$ = "NEW DELHI"

**Answer**

B4$ = "NEW DELHI"

#### Question 6

A = 4P + 5Q

**Answer**

A = 4 * P + 5 * Q

#### Question 7

AVG = (2A + 3B + 4C)/3

**Answer**

AVG = (2 * A + 3 * B + 4 * C) / 3

#### Question 8

A*B = AB + CD

**Answer**

AB = A * B + C * D

## Write down the appropriate variables for the following

#### Question 1

_________ = "Understanding Information Technology"

**Answer**

* UIT$* = "Understanding Information Technology"

#### Question 2

_________ = A * B * C

**Answer**

* Product* = A * B * C

#### Question 3

_________ = "15th August 1947"

**Answer**

* Date$* = "15th August 1947"

#### Question 4

_________ = 1/2 * A + 1/4 * B

**Answer**

* Ans* = 1/2 * A + 1/4 * B

#### Question 5

_________ = 11.99

**Answer**

* Num* = 11.99

## Define the following terms

#### Question 1

Variables

**Answer**

Variables are the assigned location in the memory used to store a value. This value can be changed at the time of execution of the program. A variable may be a single character or a set of characters. For example: A, B, B10, C$ etc. are some valid variables.

Variables are of two types:

- Numeric variables
- Alphanumeric variables

#### Question 2

Constants

**Answer**

Constants are data values that do not change at the time of execution of the program. For example: 76, -43, "Hello", etc are some constants.

Constants are of two types:

- Numeric constants
- Alphanumeric constants

#### Question 3

Numeric variables

**Answer**

Numeric variables are the variables that store integer and fractional (decimal) values. The numeric variables are used to perform all arithmetical operations.

For example, P, A2, N1, etc. are some valid variables.

#### Question 4

Alphanumeric variables

**Answer**

Alphanumeric variables are used to store alphanumeric or string constants. The set of characters to be stored must be put within double quotes (" ").

For example, A$, A1$ etc. are some valid alphanumeric variables

#### Question 5

Alphanumeric constants

**Answer**

Any set of characters can be called a string or an alphanumeric constant. They also do not change their value at the time of execution of the program. It is a sequence of alphabets, digits and special characters enclosed within double quotes.

For example, "15th AUGUST, 1947", "April 4" etc. are some valid alphanumeric constants.

#### Question 6

Numeric constants

**Answer**

Numeric constants are the numbers comprising of digits 0-9. They are positive or negative numbers that may or may not have a decimal point. These constants are used for all kinds of mathematical operations.

For example, 543, -992, 298.543, -29.82, etc. are some valid numeric constants.

## Give two differences between

#### Question 1

Numeric constants and Alphanumeric constants

**Answer**

Numeric constants | Alphanumeric constants |
---|---|

Numeric constants comprise of digits. | Alphanumeric constants comprise of a set of characters. |

Numeric constants are not enclosed in double quotes. | Alphanumeric constants are enclosed in double quotes. |

For example, 12,54 etc. | For example, "NEW DELHI - 110005", "BLOCK 2A" etc. |

#### Question 2

Numeric variables and Alphanumeric variables

**Answer**

Numeric variables | Alphanumeric variables |
---|---|

Numeric variables store numeric values. | Alphanumeric variables store alphabets, words, special characters or their combinations. |

These variables must begin with an alphabet, alphabets or alphabets followed by a number. | These variables begin with an alphabet or alphabets but must end with a dollar sign. |

These variables are used for mathematical operations. | Mathematical operations are not possible. |

For example, A, ABC, etc. | For example, A$, B12$ etc. |