Explanation:
Velocity and acceleration are vector quantities that can be changed by changing direction only (keeping magnitude constant).
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Two identical thin rings each of radius R meters are coaxially placed at a distance R meters apart. If Q1 coulomb and Q2 coulomb are respectively the charges uniformly spread on the two rings, the work done in moving a charge qfrom the centre of one ring to that of other is
|
(a) Zero |
(b) |
(c) |
(d) |
In a PNP transistor the base is the N-region. Its width relative to the P-region is
|
(a) Smaller |
(b) Larger |
(c) Same |
(d) Not related |
In a magnetic field of 0.05T, area of a coil changes from 
to 
without changing the resistance which is 2W. The amount of charge that flow during this period is
|
(a) 2.5 |
(b) 2 |
|
(c) |
(d) |
For an isotropic medium B, m, H and M are related as (where B, 
and M have their usual meaning in the context of magnetic material
|
(a) (B – M) = |
(b) |
(c) |
(d) |
A study of binary stars is most helpful in
|
(a) Finding their distances |
(b) Finding their temperature |
|
(c) Finding their masses |
(d) Verifying Newton's force law of gravitation |
Solid targets of different elements are bombarded by highly energetic electron beams. The frequency (f) of the characteristic X-rays emitted from different targets varies with atomic number Z as
|
(a) f ∝ |
(b) f ∝ |
(c) f ∝ Z |
(d) f ∝ |
