Identify the correct statements:(A) A magnetic field exerts force on…

The correct answer is Option (1) → (A), (B), (C) and (D)

The force on a charge in a magnetic field is the Lorentz force \( \vec{F} = q\,\vec{v}\times\vec{B} \), and the field of a current element is given by the Biot-Savart law.

    \( \displaystyle d\vec{B} = \frac{\mu_0}{4\pi}\,\frac{I\,d\vec{l}\times\vec{r}}{r^{3}} \)

(A) A magnetic field exerts force on a moving charge and not on a stationary charge. — Correct. For a stationary charge \( \vec{v} = 0 \), so \( q\,\vec{v}\times\vec{B} = 0 \).

(B) A moving charge produces a magnetic field. — Correct. A moving charge is a current, and every current is a source of a magnetic field.

(C) The magnetic field at a point on the axis of a current element is zero. — Correct. On the axis, \( d\vec{l} \) and \( \vec{r} \) are parallel, so \( d\vec{l}\times\vec{r} = 0 \) and \( dB = 0 \).

(D) Magnetic field \( \vec{B} \) is tangential to a magnetic field line. — Correct. A field line is drawn so that the tangent at any point gives the direction of \( \vec{B} \) there.

NCERT (2026-27):
Magnetic Field, Lorentz Force – “… (iii) The magnetic force is zero if charge is not moving (as then \( |\mathbf{v}| = 0 \)). Only a moving charge feels the magnetic force.”

Sources and Fields – “… Just as static charges produce an electric field, the currents or moving charges produce (in addition) a magnetic field, denoted by \( \mathbf{B}(\mathbf{r}) \), again a vector field.”

Magnetic Field Due to a Current Element, Biot-Savart Law – “… In Fig. 4.7, the magnetic field at any point in the direction of \( d\mathbf{l} \) (the dashed line) is zero. Along this line, \( \theta = 0,\ \sin\theta = 0 \) and from Eq. [4.7(a)], \( |d\mathbf{B}| = 0 \).”

The Magnetic Field Lines – “… (ii) The tangent to the field line at a given point represents the direction of the net magnetic field \( \mathbf{B} \) at that point.”