18 Concurrency & Threads questions from the Java bank, written for Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd.
Free to start: the 2-minute IT readiness check — six questions and a result.
A.a state where two or more threads are blocked forever, each waiting for a lock the other holds
B.an abstraction that manages a pool of worker threads and accepts tasks for asynchronous execution
C.a field modifier that guarantees reads and writes go directly to main memory, ensuring visibility across threads without locking
D.an independent path of execution within a program that the JVM can schedule to run concurrently
Answer + AI explanation with Pro
2. Which term means: "an independent path of execution within a program that the JVM can schedule to run concurrently"?
Junior
A.Deadlock
B.synchronized keyword
C.Thread
D.ExecutorService
Answer + AI explanation with Pro
3. Which statement is correct?
Junior
A.Thread — a functional interface whose run method holds the code a thread executes, returning no result
B.Thread — a field modifier that guarantees reads and writes go directly to main memory, ensuring visibility across threads without locking
C.Thread — an independent path of execution within a program that the JVM can schedule to run concurrently
D.Thread — a state where two or more threads are blocked forever, each waiting for a lock the other holds
Answer + AI explanation with Pro
4. What is synchronized keyword?
Mid
A.a modifier that acquires an object monitor lock so only one thread at a time executes the guarded block or method
B.a functional interface whose run method holds the code a thread executes, returning no result
C.an abstraction that manages a pool of worker threads and accepts tasks for asynchronous execution
D.an independent path of execution within a program that the JVM can schedule to run concurrently
Answer + AI explanation with Pro
5. Which term means: "a modifier that acquires an object monitor lock so only one thread at a time executes the guarded block or method"?
Mid
A.Runnable
B.ExecutorService
C.synchronized keyword
D.Thread
Answer + AI explanation with Pro
6. Which statement is correct?
Mid
A.synchronized keyword — an abstraction that manages a pool of worker threads and accepts tasks for asynchronous execution
B.synchronized keyword — a modifier that acquires an object monitor lock so only one thread at a time executes the guarded block or method
C.synchronized keyword — an independent path of execution within a program that the JVM can schedule to run concurrently
D.synchronized keyword — a state where two or more threads are blocked forever, each waiting for a lock the other holds
Answer + AI explanation with Pro
7. What is volatile keyword?
Mid
A.an independent path of execution within a program that the JVM can schedule to run concurrently
B.a modifier that acquires an object monitor lock so only one thread at a time executes the guarded block or method
C.an abstraction that manages a pool of worker threads and accepts tasks for asynchronous execution
D.a field modifier that guarantees reads and writes go directly to main memory, ensuring visibility across threads without locking
Answer + AI explanation with Pro
8. Which term means: "a field modifier that guarantees reads and writes go directly to main memory, ensuring visibility across threads without locking"?
Mid
A.Deadlock
B.volatile keyword
C.synchronized keyword
D.ExecutorService
Answer + AI explanation with Pro
9. Which statement is correct?
Mid
A.volatile keyword — a functional interface whose run method holds the code a thread executes, returning no result
B.volatile keyword — a field modifier that guarantees reads and writes go directly to main memory, ensuring visibility across threads without locking
C.volatile keyword — an independent path of execution within a program that the JVM can schedule to run concurrently
D.volatile keyword — a modifier that acquires an object monitor lock so only one thread at a time executes the guarded block or method
Answer + AI explanation with Pro
10. What is Deadlock?
Senior
A.a field modifier that guarantees reads and writes go directly to main memory, ensuring visibility across threads without locking
B.a state where two or more threads are blocked forever, each waiting for a lock the other holds
C.an abstraction that manages a pool of worker threads and accepts tasks for asynchronous execution
D.an independent path of execution within a program that the JVM can schedule to run concurrently
Answer + AI explanation with Pro
11. Which term means: "a state where two or more threads are blocked forever, each waiting for a lock the other holds"?
Senior
A.synchronized keyword
B.Thread
C.Deadlock
D.ExecutorService
Answer + AI explanation with Pro
12. Which statement is correct?
Senior
A.Deadlock — a modifier that acquires an object monitor lock so only one thread at a time executes the guarded block or method
B.Deadlock — an independent path of execution within a program that the JVM can schedule to run concurrently
C.Deadlock — an abstraction that manages a pool of worker threads and accepts tasks for asynchronous execution
D.Deadlock — a state where two or more threads are blocked forever, each waiting for a lock the other holds
Answer + AI explanation with Pro
13. What is ExecutorService?
Senior
A.a field modifier that guarantees reads and writes go directly to main memory, ensuring visibility across threads without locking
B.an abstraction that manages a pool of worker threads and accepts tasks for asynchronous execution
C.an independent path of execution within a program that the JVM can schedule to run concurrently
D.a modifier that acquires an object monitor lock so only one thread at a time executes the guarded block or method
Answer + AI explanation with Pro
14. Which term means: "an abstraction that manages a pool of worker threads and accepts tasks for asynchronous execution"?
Senior
A.Thread
B.volatile keyword
C.Runnable
D.ExecutorService
Answer + AI explanation with Pro
15. Which statement is correct?
Senior
A.ExecutorService — a state where two or more threads are blocked forever, each waiting for a lock the other holds
B.ExecutorService — a modifier that acquires an object monitor lock so only one thread at a time executes the guarded block or method
C.ExecutorService — a field modifier that guarantees reads and writes go directly to main memory, ensuring visibility across threads without locking
D.ExecutorService — an abstraction that manages a pool of worker threads and accepts tasks for asynchronous execution
Answer + AI explanation with Pro
16. What is Runnable?
Mid
A.a functional interface whose run method holds the code a thread executes, returning no result
B.an abstraction that manages a pool of worker threads and accepts tasks for asynchronous execution
C.a field modifier that guarantees reads and writes go directly to main memory, ensuring visibility across threads without locking
D.a state where two or more threads are blocked forever, each waiting for a lock the other holds
Answer + AI explanation with Pro
17. Which term means: "a functional interface whose run method holds the code a thread executes, returning no result"?
Mid
A.Deadlock
B.Runnable
C.Thread
D.ExecutorService
Answer + AI explanation with Pro
18. Which statement is correct?
Mid
A.Runnable — an independent path of execution within a program that the JVM can schedule to run concurrently
B.Runnable — a modifier that acquires an object monitor lock so only one thread at a time executes the guarded block or method
C.Runnable — a functional interface whose run method holds the code a thread executes, returning no result
D.Runnable — a field modifier that guarantees reads and writes go directly to main memory, ensuring visibility across threads without locking
Answer + AI explanation with Pro
Free to start
Start with a free readiness check
Sign up free for the 2-minute IT readiness check and a scored result. Answers, explanations and the AI tutor on every Concurrency & Threads question come with Pro.