List of top Physics Questions on Electricity asked in Indian Institute Of Technology Joint Admission Test for MSc

If the electric field of an electromagnetic wave is given by,
𝐸⃗ = (4𝑥̂ + 3𝑦̂)𝑒 ^{𝑖(𝜔𝑡+𝑎𝑥−600𝑦)} 
then the value of a is: (all values are in the SI units)

A plane electromagnetic wave is incident on an interface AB separating two media (refractive indices 𝑛₁ = 1.5 and 𝑛₂ = 2.0) at Brewster angle 𝜃𝐵, as schematically shown in the figure. The angle 𝛼 (in degrees) between the reflected wave and the refracted wave is:

Given that the rest mass of electron is 0.511MeV/c ² , the speed (in units of c) of an electron with kinetic energy 5.11MeV is closest to:

The plane 𝑧=0 separates two linear dielectric media with relative permittivities 𝜀_𝑟1=4 and 𝜀_𝑟2=3, respectively. There is no free charge at the interface. If the electric field in the medium 1 is 𝐸⃗ ₁=3𝑥̂+2𝑦̂ +4𝑧̂, then the displacement vector \(\overrightarrow{D_2}\) in medium 2 is: (𝜀₀ is the permittivity of free space)

Two silicon diodes are connected to a battery and two resistors as shown in the figure. The current through the battery is __________ A (rounded off to two decimal places).

Given: The forward voltage drop across each diode = 0.7 V

Two digital inputs A and B are given to the following circuit. For A = 1, B = 0, the values of X and Y are :

In a dielectric medium of relative permittivity 5, the amplitudes of the displacement current and conduction current are equal for an applied sinusoidal voltage of frequency f = 1 MHz. The value of conductivity (in Ω^-1m^-1) of the medium at this frequency is

In the circuit shown, assuming the current gain β = 100 and V_BE = 0.7 V, what will be the collector voltage V_C in V ?
Given : V_CC = 15 V, R₁ = 100 kΩ, R₂ = 50 kΩ, R_C = 4.7 kΩ, and R_E = 3.3 kΩ

At the planar interface of two dielectrics, which of the following statements related to the electric field (\(\vec{𝐸}\) ), electric displacement (\(\vec{D}\)) and polarization (\(\vec{P}\) ) is true ?

A conducting wire AB of length m has resistance of .6 Ω. It is connected to a voltage source of 0.5 V with negligible resistance as shown in the figure. The corresponding electric and magnetic fields give Poynting vectors 𝑆 (𝑟 ) all around the wire. Surface integral ∫ 𝑆 . 𝑑𝑎 is calculated over a virtual sphere of diameter 0.2 m with its centre on the wire, as shown. The value of the integral is ______W (rounded off to three decimal places)

A metallic sphere of radius 𝑅 is held at electrostatic potential 𝑉. It is enclosed in a concentric thin metallic shell of radius 2𝑅 at potential 2𝑉. If the potential at the distance \(\frac{3}{2}\) 𝑅 from the centre of the sphere is 𝑓𝑉, then the value of 𝑓 is _______ (rounded off to two decimal places).

For the following circuit, choose the correct waveform corresponding to the output signal (V_out). Given V_in = 5 sin(200πt) V, forward bias voltage of the diodes (D and Z) = 0.7 V and reverse Zener voltage = 3 V.

In the given circuit, with an ideal op-amp for what value of \(\frac{R_1}{R_2}\) the output of the amplifier V_out = V₂ - V₁ ?

Which of the following statement(s) is/are true for a LC circuit with 𝐿=25 mH and 𝐶=4 µF?

The electric field associated with an electromagnetic radiation is given by E = a(1 + cosω₁t)cosω₂t. Which of the following frequencies are present in the field?

The work done in moving a $-5\muC$ charge in an electric field $ \overrightarrow{E} = (8r sin \theta \hat{r}+ + 4r cos \theta \hat{\theta} ) V/m$, from a point $A(r, \theta) = (10,\frac{\pi}{6})$ to a point $B(r,\theta) (10.\frac{\pi}{6})$ is _____ $mj$.

In an LCR series circuit, a non-inductive resistor of 150 Ω, a coil of 0.2 H inductance and negligible resistance, and a 30 $\mu F$ capacitor are connected across an ac power source of 220 V, 50 Hz. The power loss across the resistor is _________W (Round off to 2 decimal places).

A charge $q$ is uniformly distributed over the volume of a dielectric sphere of radius $a$. If the dielectric constant $ \epsilon _r= 2$, then the ratio of the electrostatic energy stored inside the sphere to that stored outside is _________ . (Round off to I decimal place).

Consider an electrostatic field \(\overrightarrow{E}\) in a region of space. Identify the INCORRECT statement.

Consider a p-n junction at T = 300 K. The saturation current density at reverse bias is $-20 μA/cm^2$. For this device, a current density of magnitude $10 μA/cm^2$ is realized with a forward bias voltage, $V_F$. The same magnitude of current density can also be realized with a reverse bias voltage, VR. The value of I$V_F/V_R$| _________is (Round off to 2 decimal places).

The current through a series RL circuit, subjected to a constant emf \(\epsilon\), obeys \(L\frac{di}{dt}+iR=\epsilon\). Let L=1mH, R=1k\(\Omega\) and \(\epsilon\)=1V. The initial condition is i(0)=0. At t=1\(\mu s\), the current in mA is