24 real LINQ questions from the C# bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.
1. What is Deferred execution?
Mid
A.the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
B.the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
C.the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
D.a category of operators such as ToList, ToArray, Count, and First that force the query to evaluate at once rather than lazily
2. Which term means: "the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration"?
A.Deferred execution — the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
B.Deferred execution — the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
C.Deferred execution — the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
D.Deferred execution — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
A.the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
B.the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
C.the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
D.the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
5. Which term means: "the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array"?
A.Multiple enumeration pitfall — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
B.Multiple enumeration pitfall — the standard query operator that projects each element of a sequence into a new form using a transform function
C.Multiple enumeration pitfall — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
D.Multiple enumeration pitfall — the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
8. Which term means: "a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls"?
A.Query syntax — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
B.Query syntax — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
C.Query syntax — the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements
D.Query syntax — the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
A.the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
B.a category of operators such as ToList, ToArray, Count, and First that force the query to evaluate at once rather than lazily
C.a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
D.the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
A.Method syntax — the standard query operator that projects each element of a sequence into a new form using a transform function
B.Method syntax — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
C.Method syntax — the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
D.Method syntax — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
A.the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
B.the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
C.the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
D.the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements
14. Which term means: "the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true"?
A.Where operator — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
B.Where operator — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
C.Where operator — the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
D.Where operator — the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
A.Select operator — the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
B.Select operator — the standard query operator that projects each element of a sequence into a new form using a transform function
C.Select operator — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
D.Select operator — the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
A.the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements
B.the standard query operator that projects each element of a sequence into a new form using a transform function
C.the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
D.the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
20. Which term means: "the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements"?
A.Aggregate operator — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
B.Aggregate operator — the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
C.Aggregate operator — the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
D.Aggregate operator — the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements
A.Immediate execution operator — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
B.Immediate execution operator — a category of operators such as ToList, ToArray, Count, and First that force the query to evaluate at once rather than lazily
C.Immediate execution operator — the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
D.Immediate execution operator — the standard query operator that projects each element of a sequence into a new form using a transform function
Answers, AI explanations, and a scored voice mock interview
Sign up free to check your answers with explanations, ask the AI tutor anything on any question, and take one full AI mock interview — scored like a real panel.