Science (English Medium) Class 12 - CBSE Important Questions

Write suitable SQL query for the following:

Round off the value 23.78 to one decimal place.

Write suitable SQL query for the following:

Display the remainder of 100 divided by 9.

Write suitable SQL query for the following:

Remove all the expected leading and trailing spaces from a column userid of the table ‘USERS’.

Explain the following SQL function using a suitable example.

UCASE()

Explain the following SQL function using a suitable example.

TRIM()

Explain the following SQL function using a suitable example.

MID()

Explain the following SQL function using a suitable example.

DAYNAME()

Explain the following SQL function using a suitable example.

POWER()

Shreya, a database administrator has designed a database for a clothing shop. Help her by writing answers to the following questions based on the given table:

1. Write a query to display cloth names in lowercase.
2. Write a query to display the lowest price of the clothes.
3. Write a query to count the total number of clothes purchased in medium size.
   OR
   Write a query to count the year-wise total number of clothes purchased.

To display the last five rows of a series object ‘S’, you may write ______

Which of the following statement will import pandas library?

Which of the following can be used to specify the data while creating a DataFrame?

Assertion (A): DataFrame has both a row and column index.

Reasoning (R): A DataFrame is a two-dimensional labelled data structure like a table of MySQL.

Write a program to create a series of objects using a dictionary that stores the number of students in each house of class 12D of your school.

Note: Assume four house names are Beas, Chenab, Ravi, and Satluj having 18, 2, 20, and 18 students respectively and pandas library has been imported as pd.

What will be the output of the following code:

>>>import pandas as pd
>>>A = pd.Series(data = [35, 45, 55, 40])
>>>print(A > 45)

Carefully observe the following code:

import pandas as pd
Year1 = {'Q1':5000,'Q2':8000,'Q3':12000,'Q4': 18000} Year2 = {'A' :13000,'B':14000,'C':12000}
totSales = {1:Year1,2:Year2}
df = pd.DataFrame(totSales)
print(df)

Answer the following:

1. List the index of the DataFrame df
2. List the column names of DataFrame df.

Write a Python code to create a DataFrame with appropriate column headings from the list given below:

[[101,'Gurman',98], [102,'Rajveer',95], [103,'Samar' ,96], [104,'Yuvraj',88]]

Consider the given DataFrame ‘Stock’:

Write suitable Python statements for the following:

1. Add a column called Special_Price with the following data: [135,150,200,440].
2. Add a new book named ‘The Secret' with a price of 800.
3. Remove the column Special_Price.

Mr. Som, a data analyst has designed the DataFrame df that contains data about Computer Olympiad with ‘CO1’, ‘CO2’, ‘CO3’, ‘CO4’, and ‘CO5’ as indexes shown below. Answer the following questions:

1. Predict the output of the following python statement:
   i. df.shape
   ii. df[2:4]
2. Write a Python statement to display the data of the Topper column of indexes CO2 to CO4.
   OR
   Write a Python statement to compute and display the difference of data of the Tot_students column and First_Runnerup column of the above given DataFrame.

Write Python code to plot a bar chart for India’s medal tally as shown below:

Also, give a suitable python statement to save this chart.