Q1. Which of the following variable names are INVALID in R?
1_variable
variable_1
_variable
variable@

Answer:- a, c, d

Q2. The function ls() in R will

set a new working directory path
list all objects in our working environment
display the path to our working directory
None of the above

Consider the following code snippet. Based on this, answer questions 3 and 4.

Answer:- b

Q3. Which of the following command is used to access the value “Shyam”?

print(patient_list[3][2])
print(patient_list[[3]][1])
print(patient_list[[3]][2])
print(patient_list[[2]][2])

Answer:- c

Q4. The output of the code given below is

Code will throw an error.

Answer:- b

Q5. What is the output of following code?

double
integer
list
None of the above

Answer:- a

Q6. State whether the given statement is True or False.
The library reshape2 is based around two key functions named melt and cast.

True
False

Answer:- a

Q7. What is the output of following code?

6
4
2
8

Answer:- b

Create the data frame using the code given below and answer questions 8 and 9.

student_data = data.frame(student_id=c(1:4), student_name=c(‘Ram’,‘Harish’,‘Pradeep’,‘Rajesh’))

Q8. Choose the correct command to add a column named student dept to the dataframe student data.

student_datastudent dept=c(“Commerce”, “Biology”, “English”, “Tamil”)
student_data[“student dept”]= c(“Commerce”,“Biology”, “English”,“Tamil”)
student_dept= student data[c(“Commerce”,“Biology”,“English”,“Tamil”)]
None of the above

Answer:- a, b

Q9. Choose the correct command to access the element Tamil in the dataframe student_data.

student_data[[4]]
student_data[[4]][3]
student_data[[3]][4]
None of the above

Answer:- c

Q10. The command to check if a value is of numeric data type is ________.

typeof()
is.numeric()
as.numeric()
None of the above

Answer:- b