| 2651 |
Text messaging (SMS) was introduced with which generation of mobile technology? |
Computer Science/Informatics Practices
Mobile telecommunication |
Easy |
| 2652 |
Which feature is especially associated with 5G compared with earlier generations? |
Computer Science/Informatics Practices
Mobile telecommunication |
Medium |
| 2653 |
Why are mobile phones also called cellular phones? |
Computer Science/Informatics Practices
Mobile telecommunication |
Medium |
| 2654 |
Which generation was the first to be based entirely on Internet Protocol (IP) for both voice and data, enabli… |
Computer Science/Informatics Practices
Mobile telecommunication |
Hard |
| 2655 |
Which protocol is used to send email messages to a mail server? |
Computer Science/Informatics Practices
Network protocols |
Easy |
| 2656 |
Which protocol is mainly used to upload and download files between computers? |
Computer Science/Informatics Practices
Network protocols |
Easy |
| 2657 |
A user reads email on a phone and a laptop and wants messages to stay on the server and appear the same on bo… |
Computer Science/Informatics Practices
Network protocols |
Medium |
| 2658 |
What is the main job of the Internet Protocol (IP)? |
Computer Science/Informatics Practices
Network protocols |
Medium |
| 2659 |
Which protocol is designed to connect two directly linked nodes, such as a home computer dialling an Internet… |
Computer Science/Informatics Practices
Network protocols |
Hard |
| 2660 |
Which malware spreads across a network by itself without attaching to any host file? |
Computer Science/Informatics Practices
Threats and prevention |
Easy |
| 2661 |
Unwanted bulk email messages, often advertisements, are called |
Computer Science/Informatics Practices
Threats and prevention |
Easy |
| 2662 |
A free game downloaded from an unknown site works normally but secretly lets an attacker access the computer.… |
Computer Science/Informatics Practices
Threats and prevention |
Medium |
| 2663 |
A college website becomes unreachable because thousands of infected computers send it requests at the same ti… |
Computer Science/Informatics Practices
Threats and prevention |
Medium |
| 2664 |
Which description best distinguishes eavesdropping from snooping? |
Computer Science/Informatics Practices
Threats and prevention |
Hard |
| 2665 |
What does a firewall do? |
Computer Science/Informatics Practices
Network security |
Easy |
| 2666 |
Which symbol in a browser's address bar usually indicates an HTTPS connection? |
Computer Science/Informatics Practices
Network security |
Easy |
| 2667 |
A company hires an expert to break into its own systems with permission and report weaknesses. This person is |
Computer Science/Informatics Practices
Network security |
Medium |
| 2668 |
Why should antivirus software be updated regularly? |
Computer Science/Informatics Practices
Network security |
Medium |
| 2669 |
Why is HTTPS preferred over HTTP when entering a password on a website? |
Computer Science/Informatics Practices
Network security |
Hard |
| 2670 |
Which Python library is mainly used for plotting graphs and charts? |
Computer Science/Informatics Practices
Python libraries for data |
Easy |
| 2671 |
What is the output of print(np.array([1, 2, 3]) * 2) after import numpy as np? |
Computer Science/Informatics Practices
Python libraries for data |
Easy |
| 2672 |
What is the shape of np.array([[1, 2, 3], [4, 5, 6]])? |
Computer Science/Informatics Practices
Python libraries for data |
Medium |
| 2673 |
What does np.arange(1, 10, 3) produce? |
Computer Science/Informatics Practices
Python libraries for data |
Medium |
| 2674 |
Which statement correctly contrasts a NumPy array with a Pandas DataFrame? |
Computer Science/Informatics Practices
Python libraries for data |
Hard |
| 2675 |
What are the index labels of pd.Series([3, 6, 9]) when no index is given? |
Computer Science/Informatics Practices
Series |
Easy |
| 2676 |
For s = pd.Series([10, 20, 30, 40], index=['a', 'b', 'c', 'd']), what is s['b']? |
Computer Science/Informatics Practices
Series |
Easy |
| 2677 |
For the same Series s with labels a to d, how many elements does s['a':'c'] contain? |
Computer Science/Informatics Practices
Series |
Medium |
| 2678 |
What does pd.Series([4, 8, 12, 16, 20]).tail(2) return? |
Computer Science/Informatics Practices
Series |
Medium |
| 2679 |
s1 = pd.Series([1, 2, 3], index=['a', 'b', 'c']) and s2 = pd.Series([10, 20], index=['b', 'c']). What is the … |
Computer Science/Informatics Practices
Series |
Hard |
| 2680 |
df = pd.DataFrame({'Name': ['A', 'B', 'C'], 'Marks': [70, 85, 60]}). What is df.shape? |
Computer Science/Informatics Practices
DataFrames |
Easy |
| 2681 |
Which statement adds a new column named City to an existing DataFrame df with three rows? |
Computer Science/Informatics Practices
DataFrames |
Easy |
| 2682 |
Which statement removes the column Grade from df and returns the result? |
Computer Science/Informatics Practices
DataFrames |
Medium |
| 2683 |
A DataFrame has 4 rows and 3 columns. What is the shape of its transpose df.T? |
Computer Science/Informatics Practices
DataFrames |
Medium |
| 2684 |
df has shape (3, 3). The statement df2 = df.drop('Grade', axis=1) is run. What are the shapes of df and df2? |
Computer Science/Informatics Practices
DataFrames |
Hard |
| 2685 |
Which accessor selects rows and columns by their position numbers? |
Computer Science/Informatics Practices
Indexing, merging and CSV |
Easy |
| 2686 |
Which method writes a DataFrame df to a file named result.csv? |
Computer Science/Informatics Practices
Indexing, merging and CSV |
Easy |
| 2687 |
A DataFrame has index r1 to r4 and Marks 78, 45, 91 and 62. How many rows does df[df['Marks'] > 60] return? |
Computer Science/Informatics Practices
Indexing, merging and CSV |
Medium |
| 2688 |
For the same DataFrame with index r1, r2, r3, r4, which two expressions both return the rows r2 and r3? |
Computer Science/Informatics Practices
Indexing, merging and CSV |
Medium |
| 2689 |
d1 has id values 1, 2, 3 and d2 has id values 2, 3, 4, each with one other column. How many rows does pd.merg… |
Computer Science/Informatics Practices
Indexing, merging and CSV |
Hard |
| 2690 |
Which function returns the number of non-missing values in each column of a DataFrame? |
Computer Science/Informatics Practices
Descriptive statistics |
Easy |
| 2691 |
Which Pandas method gives count, mean, standard deviation, minimum, quartiles and maximum together? |
Computer Science/Informatics Practices
Descriptive statistics |
Easy |
| 2692 |
For s = pd.Series([2, 4, 4, 4, 5, 5, 7, 9]), what is s.median()? |
Computer Science/Informatics Practices
Descriptive statistics |
Medium |
| 2693 |
For u = pd.Series([10, np.nan, 30, 40]), what does u.mean() return? |
Computer Science/Informatics Practices
Descriptive statistics |
Medium |
| 2694 |
df = pd.DataFrame({'P': [3, 1], 'Q': [4, 2]}). What does df.max(axis=1) return? |
Computer Science/Informatics Practices
Descriptive statistics |
Hard |
| 2695 |
Which method arranges the rows of a DataFrame in order of the values of a column? |
Computer Science/Informatics Practices
Aggregation, grouping and pivoting |
Easy |
| 2696 |
In df.groupby('Dept')['Sal'].sum(), what does groupby('Dept') do? |
Computer Science/Informatics Practices
Aggregation, grouping and pivoting |
Easy |
| 2697 |
Dept values are HR, IT, HR, IT, Sales with salaries 30, 50, 40, 60, 20. What does df.groupby('Dept')['Sal'].s… |
Computer Science/Informatics Practices
Aggregation, grouping and pivoting |
Medium |
| 2698 |
s = pd.Series([1, 2, 3], index=['a', 'b', 'c']). What does s.reindex(['c', 'a', 'z']) contain? |
Computer Science/Informatics Practices
Aggregation, grouping and pivoting |
Medium |
| 2699 |
A sales table has columns Year, Item and Qty, and the pair (2020, Pen) appears twice. Which method can reshap… |
Computer Science/Informatics Practices
Aggregation, grouping and pivoting |
Hard |
| 2700 |
What does NaN represent in a Pandas DataFrame? |
Computer Science/Informatics Practices
Missing values and MySQL |
Easy |