✓ Board-verified
Physics · 2023 · 2 marks
CBSE 2023 · Region 5 · Set 1 · Q23
(a) Write the expression for the Lorentz force on a particle of charge q moving with a velocity v in a magnetic field B. When is the magnitude of…
Write the expression for the Lorentz force on a particle of charge $\displaystyle q$ moving with a velocity $\displaystyle \vec{\mathrm{v}}$ in a magnetic field $\displaystyle \vec{B}$. When is the magnitude of this force maximum ? Show that no work is done by this force on the particle during its motion from a point $\displaystyle \vec{r}_{1}$ to point $\displaystyle \vec{r}_{2}$.
A long straight wire AB carries a current I. A particle (mass m and charge $\displaystyle q)$ moves with a velocity $\displaystyle \vec{\mathrm{v}}$, parallel to the wire, at a distance d from it as shown in the figure. Obtain the expression for the force experienced by the particle and mention its directions.
Marking-scheme solution
(a)
during motion.
\[\begin{aligned}
& =F\left|\overrightarrow{r_{2}}-\overrightarrow{r_{1}}\right| \cos 90^{\circ} \\
& =0
\end{aligned}
\]
(b)
Force experienced by charged particle
\[\overrightarrow{F_{m}}=q(\overrightarrow{\mathrm{v}} \times \vec{B})
\]
All Moving Charges and Magnetism questions2023 question paperNCERT solutions: Moving Charges and MagnetismPractice Moving Charges and Magnetism →
More from Moving Charges and Magnetism
- A 2.0 cm segment of wire, carrying 5.0 A current in positive y-direction lies along y -axis, as shown in the figure. The magnetic field at a point (3…2024
- Two thin long parallel wires A and B are separated by a distance r and carry current I each in the same direction. The force per unit length exerted…2023
- Derive an expression for the magnetic field B, due to a circular coil of N turns, each of radius r carrying current I, at a distance ' x ' from the…2026
- Assertion: A proton and an electron enter a uniform magnetic field B with the same momentum p such that p is perpendicular to B. They describe…2024
- Beams of electrons and protons move parallel to each other in the same direction. They2023
- (i) A particle of mass m and charge q is moving with a velocity v in a magnetic field B as shown in the figure. Show that it follows a helical path.…2024
- Figure shows a narrow beam of electrons entering with a velocity of 3 × 10^7 m / s, symmetrically through the space between two parallel horizontal…2026
- A particle of mass m and charge q moving with a uniform velocity v=v_0 x i+v_0 y j enters a region with a magnetic field B=B_0 j. After some time, an…2023
CBSE Class 12 Physics past-paper question from the 2023 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.