JEE Mains · Physics · STD 12 - 4. Moving charges and magnetism
A charge particle of \(2\,\mu\,C\) accelerated by a potential difference of \(100\,V\) enters a region of uniform magnetic field of magnitude \(4\,m\,T\) at right angle to the direction of field. The charge particle completes semicircle of radius \(3\,cm\) inside magnetic field. The mass of the charge particle is \(........\times 10^{-18}\,kg\).
- A \(142\)
- B \(144\)
- C \(141\)
- D \(140\)
Answer & Solution
Correct Answer
(B) \(144\)
Step-by-step Solution
Detailed explanation
\(=\frac{m v}{q B}=\frac{\sqrt{2 k m}}{q B}, m=\frac{r^2 q^2 B^2}{2 k}\) \(m = \frac{\frac{1}{100} \times \frac{3}{100} \times 2 \times 2 \times 4 \times 10^{-3} \times 4 \times 10^{-3} \times 10^{-12}}{2 \times(100) \times 10^{-6}}\) \(=144 \times 10^{-18}\,kg\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- In a given circuit diagram, a \(5 \,{V}\) zener diode along with a series resistance is connected across a \(50 \,V\) power supply. The minimum value of the resistance required, if the maximum zener current is \(90\, {mA}\) will be \(.....\,\Omega .\)
JEE Mains 2021 Hard - An object is located at \(2\, km\) beneath the surface of the water. If the fractional compression \(\frac{\Delta V }{ V }\) is \(1.36\, \%,\) the ratio of hydraulic stress to the corresponding hydraulic strain will be ......... . [Given : density of water is \(1000\, kg m ^{-3}\) and \(\left. g =9.8 \,ms ^{-2} .\right]\)JEE Mains 2021 Medium
- Two objects are projected with same velocity ' \(u\) ' however at different angles \(\alpha\) and \(\beta\) with the horizontal. If \(\alpha+\beta=90^{\circ}\), the ratio of horizontal range of the first object to the \(2^{\text {nd }}\) object will be :JEE Mains 2023 Medium
- Find the mutual inductance in the arrangement, when a small circular loop of wire of radius ' \(R\) ' is placed inside a large square loop of wire of side \(L\) \(( L \gg R )\). The loops are coplanar and their centres coincide :
JEE Mains 2023 Medium - A transformer consisting of \(300\) turns in the primary and \(150\) turns in the secondary gives output power of \(2.2\, kW\). If the current in the secondary coils is \(10\, A\), then the input voltage and current in the primary coil areJEE Mains 2019 Medium
- The region between two concentric spheres ofradii '\(a\)' and '\(b\)', respectively (see figure), have volume charge density \(\rho = \frac{A}{r}\) where \(A\) is a constant and \(r\) is the distance from the centre. At the centre of the spheres is a point charge \(Q\). The value of \(A\) such that the electric field in the region between the spheres will be constant, is :
JEE Mains 2016 Hard
More PYQs from JEE Mains
- The sum of the roots of the equation \(x+1-2 \log _{2}\left(3+2^{x}\right)+2 \log _{4}\left(10-2^{-x}\right)=0\), is :JEE Mains 2021 Hard
- The area (in sq. units) of the largest rectangle \(ABCD\) whose vertices \(A\) and \(B\) lie on the \(x\)-axis and vertices \(C\) and \(D\) lie on the parabola, \(y = x ^{2}-1\) below the \(x\) -axis, isJEE Mains 2020 Hard
- A concave mirror for face viewing has focal length of \(0.4\,m.\) The distance at which you hold the mirror from your face in order to see your image upright with a magnification of \(5\) is......\(m\)JEE Mains 2019 Medium
- Let Ajay will not appear in JEE exam with probability \(\mathrm{p}=\frac{2}{7}\), while both Ajay and Vijay will appear in the exam with probability \(\mathrm{q}=\frac{1}{5}\). Then the probability, that Ajay will appear in the exam and Vijay will not appear is :JEE Mains 2024 Easy
- A mixture of hydrogen and oxygen has volume \(500\, {cm}^{3}\), temperature \(300\, {K}\), pressure \(400\, {kPa}\) and mass \(0.76\, {g}\). The ratio of masses of oxygen to hydrogen will be :-JEE Mains 2021 Hard
- If \(\lim _{x \rightarrow 1^{+}} \frac{(x-1)(6+\lambda \cos (x-1))+\mu \sin (1-x)}{(x-1)^3}=-1\), where \(\lambda, \mu \in \mathbb{R}\), then \(\lambda+\mu\) is equal toJEE Mains 2025 Medium