Question

------------------- converts the light from T.V. camera to VF signals.
(A) Amplifier (B) Receiver (C) Photocell (D) Rectifier

Answer 1

Hint:
- To solve this problem we have to know the functions of the components of T.V. Camera and VF signals.
- VF signals represent video frequency signals. This VF signal is the transmission output frequency of the television camera.
- The television camera is a device that makes use of an image sensor to convert an optical image to electrical signals. Basically a TV camera generates the primary components of the picture signal.

Complete step by step solution:
‘Amplify’ means increasing . A device which amplifies something is an amplifier. It is used to get a larger output signal than the input signal. It cannot convert anything.
A receiver, a device who accepts or takes something and sends it to another device. In T.V. Camera the receiver takes the signals and sends it to decards that sorts out the different sound from the signal and sends information to amplifiers.
A rectifier is a device that converts any of alternating signals to direct signals.
Photocell was invented by scientist Charles Fritts in 1883. Photocells are light sensitive image sensors. In T.V. camera photocells convert the light to video frequency signals.

Therefore, the option (c) = photocell is correct.

Note:
- VF band is a range between lowest frequency to highest frequency that is used to transmit a live television image.
- Photocell is mainly used for its high sensitivity and photoelectric detection, spectral response.
- A photocell works as a resistor that changes resistance depending on the amount of light incident on it.
- Photocells are also used in automatic light.