Download App

STD 12 - 4. Moving charges and magnetism — NEET STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceNEETSTD 12 - 4. Moving charges and magnetism4 Marks
MCQ
The figure shows three situations when an electron with velocity $\vec v$ travels through a nuniform magnetic field $\vec B$ . In each case, what is the direction of magnetic force on the electron?
  • A
    positive $z-$ axis, negative $x-$ axis, positive $y-$ axis
  • ✓
    negative $z-$ axis, negative $x-$ axis and zero
  • C
    positive $z-$ axis, positive $y-$ axis and zero
  • D
    negative $z-$ axis, positive $x-$ axis and zero
✓

Answer

Correct option: B.
negative $z-$ axis, negative $x-$ axis and zero
b
Force on electron= $q\left( {\vec v \times \vec B} \right) = e\left( {\vec B \times \vec v} \right)$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

NEET STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

A person's near point is $50 \,cm$ and his far point is $3 \,m$. Power of the lenses he requires for

$(i)$ reading and

$(ii)$ for seeing distant stars are

→
A concave mirror of focal length $f$ (in air) is immersed in water ($\mu = 4/3$). The focal length of the mirror in water will be
→
Two racing cars of masses ${m_1}$ and ${m_2}$ are moving in circles of radii ${r_1}$ and ${r_2}$ respectively. Their speeds are such that each makes a complete circle in the same duration of time $t$. The ratio of the angular speed of the first to the second car is
→
In an $LC$ oscillator, if values of inductance and capacitance become twice and eight times, respectively, then the resonant frequency of oscillator becomes $x$ times its initial resonant frequency $\omega_0$. The value of $x$ is:
→
Three mass and string system is in equilibrium. When $700\,gm$ mass is removed, then the system oscillates with a period of $3\,seconds$ . When the $500\,gm$ mass is also removed, then what will be new time period for system ..... $\sec$
→
The magnetic needle of a tangent galvanometer is deflected at an angle $30^o$ due to a magnet. The horizontal component of earth’s magnetic field $0.34 \times {10^{ - 4}}\,T$ is along the plane of the coil. The magnetic intensity is
→
Two parallel plate capacitors have their plate areas $100 \,cm ^2$ and $500 \,cm ^2$ respectively. If they have the same charge and potential and the distance between the plates of the first capacitor is $0.5 \,mm$, then the distance between the plates of the second capacitor is ........ $cm$
→
A horizontal bridge is built across a river. A student standing on the bridge throws a small ball vertically downwards with a velocity $6 ms^{-1}$. The ball strikes the water surface after $2 s$. The height of bridge above water surface is (Take $g =10 m^{-2}$ ):
→
The thermionic emission of electron is due to
→
Which wavelength of sun is used finally as electric energy ?
→