State two advantages of a C.R.O as a voltmeter

​(a) State two advantages of a C.R.O as a voltmeter

• ​Measures both D.C and A.C (1mk)

• ​Its accurate and does not take any current (1mk)

​(b) A television tube is a cathode ray tube modified. State two modifications

---

---

• Presence of magnetic coils
• Incoming signal from the aerial is fed into the grid

​(c) State the functions of the following parts of a C.R.O

(i) Grid

• Grid controls brightness of the spot

(ii) X-plates

• horizontal displacement
• time base control

(iii) Fluorescent screen

• Identify the position of the electron beam

​(d) A modern X-ray tube is shown below

​(i) Name the parts labeled A-D (2mks)

A

​Copper Anode  

B

​Tungsten Target 

C

​Filament

D

​Cooling fins  

​(ii) Give the functions of:- (1mk)

(i) Shielding with lead

​Lead absorbs the radiation (1mk)

(ii) Evacuating the tube

Prevents collisions, avoid secondary electrons (1mk)

---

---