A straight wire of diameter 0.5 mm carrying a current of 1 A is replaced by the another wire of 1 mm diameter carrying the same current. The strength of the magnetic field far away is
- one-quarter of the earlier value
- one-half of the earlier value
- twice the earlier value
- same as the earlier value
The Correct Option is D
Solution and Explanation
Current in first wire$ (I_1) $ = 1A; Diameter of second
wire $ (d_2) = 1 $ mm and current in second wire $ (I_2) = 1 A. $
Strength of magnetic field due to current flowing
in a conductor, $ (B) = \frac{{\mu}_0}{4 \pi } \times \frac{2I}{ a} \, \, or \, \, B \propto I $
Since the current in both the wires is same,
therefore there is no change in the strength of the
magnetic field.
Top Questions on Moving charges and magnetism
- A long straight current-carrying wire is placed in a uniform magnetic field of strength \( B = 0.5 \, \text{T} \). If the current in the wire is \( I = 2 \, \text{A} \) and the wire makes an angle of \( 30^\circ \) with the magnetic field, find the force per unit length on the wire.
- MHT CET - 2025
- Physics
- Moving charges and magnetism
- The correct decreasing order of spin only magnetic moment values (BM) of $ \text{Cu}^+ $, $ \text{Cu}^{2+} $, $ \text{Cr}^{2+} $ and $ \text{Cr}^{3+} $ ions is:
- JEE Main - 2025
- Chemistry
- Moving charges and magnetism
- Two long parallel wires X and Y, separated by a distance of 6 cm, carry currents of 5 A and 4 A, respectively, in opposite directions as shown in the figure. Magnitude of the resultant magnetic field at point P at a distance of 4 cm from wire Y is \( 3 \times 10^{-5} \) T. The value of \( x \), which represents the distance of point P from wire X, is\( \_\_\_\_\_\) cm. (Take permeability of free space as \( \mu_0 = 4\pi \times 10^{-7} \) SI units.)
- JEE Main - 2025
- Physics
- Moving charges and magnetism
- Total number of molecules/species from the following which will be paramagnetic is ________________________. \[ O_2, O_2^+, O_2^-, NO, NO_2, CO, K_2[NiCl_4], [Co(NH_3)_6]Cl_3, K_2[Ni(CN)_4] \]
- JEE Main - 2025
- Chemistry
- Moving charges and magnetism
The magnetic moment is associated with its spin angular momentum and orbital angular momentum. Spin only magnetic moment value of Cr^{3+ ion (Atomic no. : Cr = 24) is:
- CBSE CLASS XII - 2025
- Chemistry
- Moving charges and magnetism
Questions Asked in NEET exam
- Match List I with List II:
List I List II A Two or more alternative forms of a gene I Back cross B Cross of F1 progeny with homozygous recessive parent II Ploidy C Cross of F progeny with any of the parents III Allele D Number of chromosome sets in plant IV Test cross
Choose the correct answer from the options given below:- NEET (UG) - 2024
- Regulation of Gene Expression
In the above diagram, a strong bar magnet is moving towards solenoid-2 from solenoid-1. The direction of induced current in solenoid-1 and that in solenoid-2, respectively, are through the directions :- NEET (UG) - 2024
- Solenoids and Toroids
- 1 gram of sodium hydroxide was treated with 25 ml. of 0.75 M HCI solution, the mass of sodium hydroxide left unreacted is equal to
- NEET (UG) - 2024
- Structural Representations Of Organic Compounds
- Two heaters A and B have power rating of 1 kW and 2 kW, respectively. Those two are first connected in series and then in parallel to a fixed power source. The ratio of power outputs for these two cases is :
- NEET (UG) - 2024
- work, energy and power
The following graph represents the T-V curves of an ideal gas ( where T is the temperature and V the volume) at three pressures P1, P2 and P3 compared with those of Charles's law represented as dotted lines.
Then the correct relation is :- NEET (UG) - 2024
- Ideal Gases
Concepts Used:
Moving Charges and Magnetism
Moving charges generate an electric field and the rate of flow of charge is known as current. This is the basic concept in Electrostatics. Another important concept related to moving electric charges is the magnetic effect of current. Magnetism is caused by the current.
Magnetism:
- The relationship between a Moving Charge and Magnetism is that Magnetism is produced by the movement of charges.
- And Magnetism is a property that is displayed by Magnets and produced by moving charges, which results in objects being attracted or pushed away.
Magnetic Field:
Region in space around a magnet where the Magnet has its Magnetic effect is called the Magnetic field of the Magnet. Let us suppose that there is a point charge q (moving with a velocity v and, located at r at a given time t) in presence of both the electric field E (r) and the magnetic field B (r). The force on an electric charge q due to both of them can be written as,
F = q [ E (r) + v × B (r)] ≡ EElectric +Fmagnetic
This force was based on the extensive experiments of Ampere and others. It is called the Lorentz force.