Subject :NSO Class : Class 6
In which of the following a permanent magnet is not used?
A In magnetic door catchers
B Loudspeakers
C In compasses
D None of these
Ans 1:
Class : Class 6
Loud speakers use electromagnets as they dont need magnetic force when not in use so ans is B
Ans 2:
Class : Class 9
loud speakers have both electromagnets and permanent magnets
Ans 3:
Class : Class 7
Don't loudspeakers use electromagnets?
Ans 4:
Class : Class 9
The answer is B as loudspeakers use electromagnets and the magnetic field isn't there always .
Ans 5:
Class : Class 9
Loudspeakers use electromagnets.So,the answer should be (B)
Ans 6:
Class : Class 9
Ans 7:
Class : Class 7
answer should be b
Ans 8:
Class : Class 9
Ans 9:
Class : Class 6
answer is B so obvious
Ans 10:
Class : Class 3
Loud speakers use permanent magnets
Ans 11:
Class : Class 10
Loudspeakers use electromagnets, so the answer is option B
Ans 12:
Class : Class 9
they use both so the answer is d
Ans 13:
Class : Class 9
Loudspeakers use electromagnets so it should be answer b
Ans 14:
Class : Class 8
But all of them use permanent magnets...so D is correct
Ans 15:
Class : Class 10
answer will be b as loudspeakers use electromagents
Ans 16:
Class : Class 7
Loudspeakers use electromagnets.