- Is towards east at A and towards west at B.
- Is towards west at A and towards east at B.
- Is towards east at both A and B.
- Is towards west at both A and B.
Explanation:
According to the right-hand thumb rule, if we curl the fingers of our right hand in the direction of the current flowing, then the stretching of the thumb will show the direction of the magnetic field developed due to it and vice versa.
Let north-south is along x axis and east-west is along y axis. Circular wire is in xz plane. Then point A will lie on positive y axis and B on negative y axis. On looking from point B, current is flowing in anticlockwise direction so the magnetic field will point from right to left. Hence, the magnetic field due to the loop will be towards west at both A and B.
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Which of the following rays are not electromagnetic waves
|
(a) g-rays |
(b) b-rays |
(c) Heat rays |
(d) X-rays |
When neutrons are bombarded on nucleus of
, the number of emitted neutrons will be
|
(a) 1 |
(b) 2 |
(c) 3 |
(d) 4 |
The wavelength of light in two liquids ‘x' and ‘y' is 3500 Å and 7000 Å, then the critical angle of x relative to y will be
|
(a) 60° |
(b) 45° |
(c) 30° |
(d) 15° |
An a particle is accelerated through a p.d of
volt then K.E. of particle will be
|
(a) 8 MeV |
(b) 4 MeV |
(c) 2 MeV |
(d) 1 MeV |
Which one of the following statements is not correct
|
(a) A diode does not obey Ohm's law |
|
(b) A PN junction diode symbol shows an arrow identifying the direction of current (forward) flow |
|
(c) An ideal diode is an open switch |
|
(d) An ideal diode is an ideal one way conductor |
The addition of antimony atoms to a sample of intrinsic germanium transforms it to a material which is
|
(a) Superconductor |
(b) An insulator |
|
(c) N-type semiconductor |
(d) P-type semiconductor |
Two resistances are connected in two gaps of a metre bridge. The balance point is 20 cm from the zero end. A resistance of 15 ohms is connected in series with the smaller of the two. The null point shifts to 40 cm. The value of the smaller resistance in ohms is
|
(a) 3 |
(b) 6 |
(c) 9 |
(d) 12 |
A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will
|
(a) Become infinite |
(b) Become small, but non–zero |
|
(c) Remain unchanged |
(d) Become zero |