Question
In the given figure net magnetic field at O will be
(a)  
|
(b) 
|
(c) |
(d) |
✓
Answer
(b)
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The idea of secondary wavelets for the propagation of a wave was first given by
|
(a) Newton |
(b) Huygen |
(c) Maxwell |
(d) Fresnel |
The concepts of holes is introduced based on:
Consider an electron in the nth orbit of a hydrogen atom in the Bohr model. The circumference of the orbit can be expressed in terms of the de Broglie wavelength λ of that electron as
|
(a) (0.259)n λ |
(b) |
(c) (13.6) λ |
(d) n λ |
Two bulbs of 100 W and 200 W working at 220 volt are joined in series with 220 volt supply. Total power consumed will be approximately.
|
(a) 65 watt |
(b) 33 watt |
(c) 300 watt |
(d) 100 watt |
The efficiency of transformer is very high because
|
(a) There is no moving part in a transformer |
(b) It produces very high voltage |
|
(c) It produces very low voltage |
(d) None of the above |
Doppler's effect is sound in addition of relative velocity between source and observer, also depends while source and observer or both are moving. Doppler's effect in light depend only on the relative velocity of source and observer. The reason of this is.
If 4 
energy is required to move a charge of 0.25 coulomb between two points. Then what will be the potential difference between them
|
(a) 178 V |
(b) 256 V |
(c) 356 V |
(d) None of these |
The binding energy of a nucleus is equivalent to:
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 |
If a 30 V, 90 W bulb is to be worked on a 120 V line, a resistance of how many ohms should be connected in series with the bulb
|
(a) 10 ohm |
(b) 20 ohm |
(c) 30 ohm |
(d) 40 ohm |