Question

A student finds a three legged device in a given mixed collection of items while performing an experiment. Which device is it?
A. Resistor
B. Capacitor
C. Transistor
D. Diode

Answer 1

Hint: In order to figure out which device student finds from a mixed collection of items while performing an experiment, we need to understand about basic structure of each component device which are given in options, so we will define each component one by one and later will find out which one has a three legged device among them from the given options.

Complete answer:
Considering the first option which is given as Resistor. A resistor is an electronic component which has the ability to oppose the flow of current flowing in the wire and resistor is a linear structure in physicality which has two legs, so it does not have a three leg so, resistor cannot be the correct option.

Capacitor is an electrical component which has the ability to store charge after charging through a battery, in physical structure it has two legs so, capacitor cannot be the correct option.

Transistor is a semiconductor device component which is used to amplify electronic signals and it is used in modern electronics, it is either a combination of PNP junction or NPN junction which has three legs in physical structure, hence Transistor has three legs so it can be the correct option.

Diode is an electronic device which allows the current to flow in one direction only and it is also used in modern electronic circuits widely, physically, it is two legged structure, hence it cannot be the correct option. So, a transistor has a three legged structure and it’s the device which the student finds out among the mixed collection of items.

Hence, the correct option is C.

Note: It should be remembered that, In PNP and NPN transistors P and N stands for Positive negative positive and Negative positive Negative which means the middle terminal is base and other two are collector and emitter in the semiconductor device. Transistors are mainly used as ON or OFF functions in digital electronics as binary operations.