Question
Which of the following statements accurately describes
the role of system calls in an operating system?ÂSolution
System calls serve as the primary mechanism by which user applications request services from the operating system's kernel. They provide an essential interface between the application layer and the hardware or system resources, enabling tasks such as file management, process control, and network communication. For example, when an application needs to read a file, it invokes a system call, which then passes the request to the operating system. The operating system processes this request and returns the necessary data or confirmation to the application. This functionality is vital for resource management and system integrity, as system calls ensure that applications do not directly interact with hardware resources, thus maintaining security and stability. System calls bridge the gap between user-mode applications and kernel-mode operations, allowing applications to perform complex tasks without needing to understand the underlying hardware intricacies. Option A (User applications communication) - System calls do not facilitate direct communication between applications; instead, they allow applications to interact with the operating system. Option C (Commands executed by the kernel) - While system calls are invoked by user applications to communicate with the kernel, they are not commands executed by the kernel themselves. Option D (User-defined functions) - System calls are not user-defined; they are predefined functions provided by the operating system for application use. Option E (Inter-process communication) - System calls can facilitate inter-process communication (IPC) but are not themselves a form of IPC.
- A man purchased a laptop for Rs. 15,000 and a mobile phone for Rs. 10,000. He sold the laptop at a profit of 20% and the mobile phone at a loss of 10%. Fin...
A bought an article at 30% less of the marked price and sold it at 12% more than the marked price. Find the profit earned by him.
- A shopkeeper adds 40% to the cost price of a chair and sells it after offering a 25% discount on the marked price. If the chair is sold for Rs. 2,100, find...
- A dealer sold a furniture item for Rs. 300 after allowing a discount of ‘q%’ on its marked price. If the marked price of the item is Rs. 400, then find...
The average cost price of two items is Rs. 750. The first item is sold at a 15% profit, and the second item is sold at a 20% loss. Given that the combin...
Nikhil purchased a house for Rs. 20,00,000/- and gave it on rent immediately at the rate of Rs. 15,000/- per month. After five months, he sold the house...
Aman bought two guitars, ‘P’ and ‘Q’, with cost prices in the ratio 7:9, and sold them at a loss of 10% and a profit of 30%, respectively. If th...
A person bought an article and sold it at a loss of 20%. If he had bought it at 10% loss and sold it for 74 more, he would have gained 30%. Find the pro...
A and B started a partnership business investing in the ratio of 3 : 8. C joined them after 4 months with an amount equal to 3/4th of B. What was their...
A shopkeeper bought 200 articles at ₹40 each. He sold 120 articles at ₹50 each and the rest at ₹60 each. What is the profit percentage earned by t...