JEE Main 2022 · 28 June · morning · Single correct · +4 / −1
For using a multimeter to identify diode from electrical components, choose the correct statement out of the following about the diode :
- (a) It is two terminal device which conducts current in both directions.
- (b) It is two terminal device which conducts current in one direction only.
- (c) It does not conduct current gives an initial deflection which decays to zero.
- (d) It is three terminal device which conducts current in one direction only between central terminal and either of the remaining two terminals
Answer and solution
Answer (b) It is two terminal device which conducts current in one direction only.
Solution
Physics sir · 3 steps
Swap the multimeter leads: a diode shows low resistance one way and very high resistance the other way.
- The test. Connect the multimeter across the two terminals, note the reading, then swap the leads. A component is recognised by how its readings change between the two connections.
- Why a diode. A p-n junction conducts when forward biased and almost blocks current when reverse biased. So a diode reads low resistance in one direction and very high resistance in the other.
Option Behaviour on the multimeter Component it describes (a) Same reading both ways, conducts in both directions resistor (b) Two terminals, conducts one way only diode (c) Brief deflection that decays to zero as it charges capacitor (d) Three terminals, conducts one way between the base and each of the other two transistor - So. The diode is the two-terminal device that conducts current in one direction only, which is option (b).
The idea to keep. In the multimeter test, the resistor reads the same both ways, the diode conducts one way only, the capacitor kicks and decays, and the transistor has three terminals. Learn all four together.
Answer from the NTA final answer key. Solution by PrepWiser.