G12 Quiz 2 Cathode Rays

Explanation
In a cathode-ray tube, the part that emits the electrons is the cathode. The cathode is negatively charged and when a voltage is applied, it releases a stream of electrons. These electrons are then accelerated towards the anode, creating a beam of electrons that can be manipulated to create images on the screen. Therefore, option B is the correct answer as it represents the cathode in the diagram.

Explanation
Charged particles emitted from the cathode of an oscilloscope are called electrons. Electrons have a negative charge.

Explanation
The type of charge on the anode is positive. This charge is chosen because cathode rays are negatively charged particles, so they are attracted to the positively charged anode.

Explanation
In a cathode-ray tube, the cathode emits electrons which are accelerated towards the anode due to the potential difference between them. The anode is positively charged, attracting the negatively charged electrons. The electrons then pass through the deflection plates, which are perpendicular to each other. The purpose of the deflection plates is to control the path of the electrons and make them hit a specific spot on the screen. In this case, the student wants the spot at point P on the screen. To achieve this, the top Y plate should be positive, as it will repel the electrons upwards, and the anode should also be positive, as it will attract the electrons towards it.

Explanation
The line in the table that shows the charge and the temperature of the anode is C.

Explanation
The cathode-ray beam is deflected towards the positive plate because the beam consists of negatively charged particles (electrons). When the beam passes through the electric field between the charged parallel plates, the positive plate attracts the negatively charged electrons, causing them to move towards it. Therefore, the beam is deflected towards the positive plate.

Explanation
In a cathode-ray oscilloscope tube, the spot on the screen is created by a beam of electrons emitted from the cathode and deflected by the charged plates. When the charged plates are rearranged, the electric field between them changes, causing the beam of electrons to be deflected in a different direction. Therefore, the new position of the spot on the screen will be shown in diagram B.

Explanation
Cathode rays are composed of electrons. This is because cathode rays are produced when a high voltage is applied across a cathode and an anode in a vacuum tube, causing electrons to be emitted from the cathode. These electrons then travel in a straight line towards the anode, forming the cathode rays. Therefore, the correct answer is electrons.

Explanation
The correct answer is between C and D. This is because in a cathode ray tube, the cathode (negative electrode) is connected to terminal D, and the anode (positive electrode) is connected to terminal C. The potential difference (p.d.) is applied between the cathode and the anode to create an electric field that accelerates the cathode rays towards the anode. Therefore, the p.d. is connected between terminals C and D.

Explanation
The figure shows a type of tube in which cathode rays can be produced. In order for cathode rays to be produced, the tube must be evacuated of all air particles. This creates a vacuum inside the tube, meaning that there is no air or any other particles occupying the remaining space. Therefore, the correct answer is Vacuum.