Question

One of the uses of a cathode ray tube is

• A. They are used in mobile phones and WIFI
• B. They are used to break DNA molecules
• C. They are used to check the waveforms of electric signals
• D. They are used in dental practices

Answer 1

The correct option is C

They are used to check the waveforms of electric signals

Explanation of Correct Answer:

Option (C):

1. A cathode-ray tube is a vacuum tube.
2. It contains one or more electron guns.
3. These electron guns produce electron beams.
4. The electrons beans are adjusted in such a way that they show pictures on a phosphorescent screen.
5. Hence, one of the uses of a cathode ray tube is that they are used to check the waveforms of electric signals.

Explanation of Incorrect Answer:

Option (A):

Mobile phones and WiFi work with the help of LCD screens.

Option (B):

Enzymes are used to break DNA molecules.

Option (D):

Lasers are generally used in dental practices.

Hence, the correct answer is option (C).