Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    2
    ReputationRep:
    I know this'll seem really obvious to most of you, but I've never studied 'inductance' so have no idea where to even start :p:

    'The current in a coil changes from 5A to 2A in 0.05 seconds and induces a voltage of 30V in the coil, the inductance of the coil is?
    a) 0.2H
    b) 0.5H
    c) 1.5H
    d) 2.0H

    (I don't even know what H is )
    Thank-you m'dears!
    Offline

    6
    ReputationRep:
    EMF = inductance x rate of change of current

    dI/dt = 3/0.05 = 60

    so L = 30 / 60 = 0.5H
    Offline

    0
    ReputationRep:
    I've almost passed my level 2 c&g tech cert now, but i'm trying to get ahead of the game, if i remember correctly H is (Henry) which is a measure of the inductance of a coil.
    I just got this question on a Mock exam and i worked it out like this:

    Inductance (L) =
    Current change, in this instance (5A-2A) / Rate of change in seconds (0.05s)
    so:
    3A/0.05s = 60
    30v/ 60 = 0.5 Henry
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Would you like to hibernate through the winter months?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.