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CBSE Class 12-science Answered

what are the use of transistors and resistors in electric water buzzer please give detailed discription of use these two elements in buzzer circuitory ? and why are they used?
Asked by bhuwnesh16 | 07 Nov, 2016, 09:53: AM
answered-by-expert Expert Answer
A transistor is used in the circuit so that it acts as an amplifier when a certain level of voltage is reached. In the water level buzzer circuit when the water is reached at a certain level, the positive end of the battery gets connected to the base of the transistor and the current starts flowing from collector to emitter. This causes the LED or the BUZZER to glow/ring indicating that a certain level is reached.
 
Resistors are used in the circuit to limit the current to a certain level as LED's or buzzers might get heated up due to large current.
 
A simple circuit for water level buzzer is available online. Now, if transistors are not used, then any slight change in voltage will not be detected as LED's need a certain level of voltage to start glowing.
Answered by Romal Bhansali | 08 Nov, 2016, 10:16: AM

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CBSE 12-science - Physics
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