Which was the first computer to use transistor instead of vacuum tubes?(A) Intel-650(B) Burroughs E-101(C) Datamatic- 1000(D) IBM- 1401(E) None of the above

The first computer to use transistors instead of vacuum tubes was the IBM 1401.
Explanation:
The IBM 1401 was an early transistorized computer, introduced in 1959. It was one of the first computers to utilize transistors for switching, rather than the vacuum tubes that had been used in earlier computers. The transition from vacuum tubes to transistors marked a significant improvement in the reliability, size, and power consumption of computers.
Key Facts:
• Transistors replaced vacuum tubes in IBM 1401, making it faster, smaller, and more energy-efficient than previous tube-based computers.
• The IBM 1401 was widely used in business and administrative applications, particularly for tasks like accounting and data processing.
Thus, the correct answer is:
(D) IBM 1401.
Other Computers Mentioned:
• Intel-650: The Intel 650 is not a well-known early computer and is more related to Intel's microprocessors in later years.
• Burroughs E-101: This was another early computer but not the first to use transistors.
• Datamatic-1000: Also an early transistorized computer, but the IBM 1401 preceded it in the widespread use of transistors.
• None of the above: This option is incorrect as IBM 1401 was indeed the correct answer.