- AHigh retentivity and high coercive force.
- BHigh retentivity and low coercive force.
- CLow retentivity and high coercive force.
- DLow retentivity and low coercive force.
Explanation:
Electro magnets arc made of soft iron because soft iron has Low retentivity and Low coercive force.
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The masses of neutron and proton are 1.0087 a.m.u. and 1.0073 a.m.u. respectively. If the neutrons and protons combine to form a helium nucleus (alpha particles) of mass 4.0015 a.m.u. The binding energy of the helium nucleus will be (1 a.m.u.= 931 MeV)
|
(a) 28.4 MeV |
(b) 20.8 MeV |
(c) 27.3 MeV |
(d) 14.2 MeV |
A straight wire of length (
metre is carrying a current of 2A and the magnetic field due to it is measured at a point distant 1 cm from it. If the wire is to be bent into a circle and is to carry the same current as before, the ratio of the magnetic field at its centre to that obtained in the first case would be
|
(a) 50 : 1 |
(b) 1 : 50 |
(c) 100 : 1 |
(d) 1 : 100 |
The plate resistance of a triode is 2.5 × 104 W and mutual conductance is 2 × 10–3 mho. What will be the value of amplification factor
|
(a) 50 |
(b) 1.25 × 107 |
(c) 75 |
(d) 2.25 × 107 |
There are three resistance coils of equal resistance. The maximum number of resistances you can obtain by connecting them in any manner you choose, being free to use any number of the coils in any way is
|
(a) 3 |
(b) 4 |
(c) 6 |
(d) 5 |
What will be the colour of sky as seen from the earth, if there were no atmosphere
|
(a) Black |
(b) Blue |
(c) Orange |
(d) Red |
Two resistances
and
when connected in series and parallel with 120 V line, power consumed will be 25 W and 100 W respectively. Then the ratio of power consumed by
to that consumed by
will be
|
(a) 1 : 1 |
(b) 1 : 2 |
(c) 2 : 1 |
(d) 1 : 4 |