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An ideal inductor-resistor-battery circuit is switched on at $t=0$ s. At time $t$, the current is $i=i_0(1-e^{-t/\tau})$, where $i_0$ is the steady-state value. The time at which the current becomes $0.5i_0$ is: [Given $\ln(2)=0.693$]
If $\vec{E}$ and $\vec{B}$ represent the electric field vector and magnetic field vector, respectively, in an electromagnetic wave then the direction of EM wave is along:
The velocity of electromagnetic radiation in a medium of permittivity $\varepsilon_0$ and permeability $\mu_0$ is given by:
In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of $2.0 \times 10^{10} \text{ Hz}$ and amplitude $48 \text{ V m}^{-1}$. Then the amplitude of the oscillating magnetic field is: (Speed of light in free space $= 3 \times 10^8 \text{ m s}^{-1}$)
Two identical capacitors $C_1$ and $C_2$ of equal capacitance are connected as shown in the circuit. Terminals a and b of the key k are connected to charge capacitor $C_1$ using a battery of emf $V$ volt. Now disconnecting a and b terminals, terminals b and c are connected. Due to this, what will be the percentage loss of energy?
The height at which the weight of a body becomes 1/16th, its weight on the surface of the earth (radius R), is:
Charges $+q$ and $-q$ are placed at points A and B, respectively, which are at a distance $2L$ apart. C is the midpoint between A and B. The work done in moving a charge $+Q$ along the semicircle CRD is:
If the mean free path of atoms is doubled then the pressure of the gas will become:
Four equal charges Q are placed at the four corners of a square of each side is ‘a’. Work done in removing a charge –Q from its centre to infinity is
Out of the following options which one can be used to produce a propagating electromagnetic wave?
An electromagnetic wave is moving along negative $z$ ($-z$) direction and at any instant of time, at a point, its electric field vector is $3\hat j \text{ V/m}$. The corresponding magnetic field at that point and instant will be: (Take $c=3\times10^8 \text{ ms}^{-1}$)
The dimensions of mutual inductance (M) are:
Two thin dielectric slabs of dielectric constants $K_1$ and $K_2$ ($K_1 < K_2$) are inserted between plates of a parallel plate capacitor, as shown in the figure. The variation of electric field $E$ between the plates with distance $d$ as measured from the plate P is correctly shown by:
A small sphere of radius $r$ falls from rest in a viscous liquid. As a result, heat is produced due to the viscous force. The rate of production of heat when the sphere attains its terminal velocity is proportional to:
For an ideal solution, the correct option is :
An EM wave is propagating in a medium with a velocity $\vec{v} = v\hat{i}$. The instantaneous oscillating electric field of this EM wave is along the $+y$ axis. The direction of the oscillating magnetic field of the EM wave will be along:
A parallel plate air capacitor is charged to a potential difference of $V$ volts. After disconnecting the charging battery, the distance between the plates of the capacitor is increased using an insulating handle. As a result the potential difference between the plates:
A capacitor is charged by a battery. The battery is removed and another identical uncharged capacitor is connected in parallel. The total electrostatic energy of the resulting system
Match List - I with List - II: **List - I (Electromagnetic waves)** (a) AM radio waves (b) Microwaves (c) Infrared radiation (d) X-rays **List - II (Wavelength)** (i) $10^{-10} \text{ m}$ (ii) $10^{2} \text{ m}$ (iii) $10^{-2} \text{ m}$ (iv) $10^{-4} \text{ m}$
A conducting sphere of radius R is given a charge Q. The electric potential and the electric field at the centre of the sphere respectively are: