JEE Mains · Physics · STD 12 -Electromagnetic induction
- JEE Mains 2023
- Hard
- Numerical
The magnetic field \(B\) crossing normally a square metallic plate of area \(4\,m ^2\) is changing with time as shown in figure. The magnitude of induced \(emf\) in the plate during \(t=2\,s\) to \(t=4\,s\), is \(..........\,mV\)

Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(8\)
Step-by-step Solution
Detailed explanation
\(m =\tan \theta=\frac{10}{5}=2\)
\(B = mt\)
\(B =2 t\)
\(\varepsilon=\left|\frac{ d \phi}{ dt }\right|=\frac{ d ( BA )}{ dt }=\frac{ AdB }{ dt }\)
\(\varepsilon=\frac{4 d (2 t )}{ dt }=4 \times 2=8\,mVolt\)
More questions from Physics
- A cubical block of density \(\rho_{ b }=600 kg / m ^3\) floats in a liquid of density \(\rho_{ e }=900 kg / m ^3\). If the height of block is \(H=8.0 cm\) then height of the submerged part is _________ cm .JEE Mains 2026 Hard
- Given below are two statements : \(Statement\) \((I)\) : Planck's constant and angular momentum have same dimensions. \(Statement\) \((II)\) : Linear momentum and moment of force have same dimensions. In the light of the above statements, choose the correct answer from the options given below :JEE Mains 2024 Hard
- The force is given in terms of time \(t\) and displacement \(x\) by the equation \({F}={A} \cos {Bx}+{C} \sin {Dt}\) The dimensional formula of \(\frac{{AD}}{{B}}\) is -JEE Mains 2021 Medium
- The expression given below shows the variation of velocity \((v)\) with time (t), \(v=\mathrm{At}^2+\frac{\mathrm{Bt}}{\mathrm{C}+\mathrm{t}}\). The dimension of ABC is :JEE Mains 2025 Hard
- A proton and a deutron ( \(\mathrm{q}=+\mathrm{e}, m=2.0 \mathrm{u})\) having same kinetic energies enter a region of uniform magnetic field \(\vec{B}\), moving perpendicular to \(\vec{B}\). The ratio of the radius \(r_d\) of deutron path to the radius \(r_p\) of the proton path is _______.JEE Mains 2024 Hard
- Two moles of an ideal monoatomic gas occupies a volume \(V\) at \(27^o C\). The gas expands adiabatically to a volume \(2\ V\). Calculate \((a)\) the final temperature of the gas and \((b)\) change in its internal energy.JEE Mains 2018 Medium
More PYQs from JEE Mains
- A stationary horizontal disc is free to rotate about its axis. When a torque is applied on it, its kinetic energy as a function of \(\theta ,\) where \(\theta \) is the angle by which it has rotated, is given as \(k\theta ^2.\) If its moment of inertia is \(I\) then the angular acceleration of the disc isJEE Mains 2019 Hard
- The Young's modulus of steel wire of radius \(r\) and length \(L\) is \(Y\). If the radius \(r\) and length \(L\) of the wire are doubled then the value of \(Y\)JEE Mains 2026 Easy
- A radioactive sample is undergoing \(\alpha\) decay. At any time \(t_{1}\), its activity is \(A\) and another time \(t _{2}\), the activity is \(\frac{ A }{5}\). What is the average life time for the sample?JEE Mains 2021 Hard
- In a photoelectric experiment ultraviolet light of wavelength \(280\, {nm}\) is used with lithium cathode having work function \(\phi=2.5\, {eV}\). If the wavelength of incident light is switched to \(400\, {nm}\), find out the change in the stopping potential (in \({V}\)). \(\left({h}=6.63 \times 10^{-34}\, {J} \cdots\right.\), \(\left.{c}=3 \times 10^{8} \,{ms}^{-1}\right)\)JEE Mains 2021 Hard
- A force \(\overrightarrow{ F }=(\hat{ i }+2 \hat{ j }+3 \hat{ k }) N\) acts at a point \((4 \hat{ i }+3 \hat{ j }-\hat{ k }) m \cdot\) Then the magnitude of torque about the point \((\hat{i}+2 \hat{j}+\hat{k}) m\) will be \(\sqrt{ x } N - m .\) The value of \(x\) is\(........\)JEE Mains 2020 Medium