Roentgen worked with which device?

Roentgen worked with which device?

• A. Geissler tube
• B. Crookes tube
• C. Tesla coil
• D. Cathode ray tube

Answer: (B)

Roentgen’s key discovery came from using a Crookes tube, a sealed vacuum tube that generates cathode rays when high voltage is applied. He observed that a fluorescent screen near the tube would glow even when shielded, indicating radiation beyond visible light—what we now call X-rays. The Crookes tube’s high vacuum and geometry were essential for producing and directing those rays, making it the device most closely tied to his breakthrough. Other devices listed either served different purposes or were broader categories: the Geissler tube is an earlier, less suitable gas-discharge tube; the Tesla coil is a high-voltage power source used in other experiments; a cathode ray tube is a general class that includes Crookes tubes but isn’t the precise historical instrument Roentgen used.

Roentgen’s key discovery came from using a Crookes tube, a sealed vacuum tube that generates cathode rays when high voltage is applied. He observed that a fluorescent screen near the tube would glow even when shielded, indicating radiation beyond visible light—what we now call X-rays. The Crookes tube’s high vacuum and geometry were essential for producing and directing those rays, making it the device most closely tied to his breakthrough. Other devices listed either served different purposes or were broader categories: the Geissler tube is an earlier, less suitable gas-discharge tube; the Tesla coil is a high-voltage power source used in other experiments; a cathode ray tube is a general class that includes Crookes tubes but isn’t the precise historical instrument Roentgen used.