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

A transistor (β=100, 𝑉𝐵𝐸 = 0.7𝑉) is connected as shown in the circuit below.

The current IC will be mA. (Rounded off to two decimal places)

The Fermi energy of a system is 5.5eV. At 500K, the energy of a level for which the probability of occupancy is 0.2, is ________eV. (Rounded off to two decimal places) (Boltzmann constant 𝑘_𝐵 = 8.62x10⁻⁵ eV/K)

A stationary nitrogen (\(^{14}_7N\)) nucleus is bombarded with α- particle (\(^{4}_2He\)) and the following nuclear reaction takes place:

If the kinetic energies of \(^4_2\) and \(^4_2H\) are 5.314MeV and 4.012MeV, respectively, then the kinetic energy of \(^{17}_80\) is MeV. (Rounded off to one decimal place) 
(Masses are given in units of 𝑢 = 931.5MeV/c² )

A collimated light beam of intensity 𝐼₀ is incident normally on an air-dielectric (refractive index 2.0) interface. The intensity of the reflected light is _______𝐼₀. (Rounded off to two decimal places)

A satellite of mass 10kg, in a circular orbit around a planet, is having a speed 𝑣=200m/s. The total energy of the satellite is _______kJ. (Rounded off to nearest integer)

For a simple cubic crystal, the smallest inter-planar spacing d that can be determined from its second order of diffraction using monochromatic X-rays of wavelength 1.32Å is _________Å. (Round off to two decimal places)

Consider a thick biconvex lens (thickness t=4cm and refractive index n=1.5) whose magnitudes of the radii of curvature R1 and R2, of the first and second surfaces are 30cm and 20cm, respectively. Surface 2 is silvered to act as a mirror. A point object is placed at point A on the axis (OA= 60cm) as shown in the figure. If its image is formed at point Q, the distance d between O and Q is_____ cm. (Rounded off to two decimal places)

In the Taylor expansion of function, 𝐹(𝑥)=𝑒^𝑥 sin 𝑥, around 𝑥 = 0, the coefficient of 𝑥⁵ is ______. (Rounded off to three decimal places)

A particle of mass 1kg, initially at rest, starts sliding down from the top of a frictionless inclined plane of angle \(\frac{𝜋}{6}\)\(\frac{\pi}{6}\) (as schematically shown in the figure). The magnitude of the torque on the particle about the point O after a time 2seconds is ______N-m. (Rounded off to nearest integer)

(Take g = 10m/s²)

Which of the following fields has non-zero curl ?

A linearly polarized light of wavelength 590 nm is incident normally on the surface of a 20 μm thick quartz film. The plane of polarization makes an angle 30° with the optic axis. Refractive indices of ordinary and extraordinary waves differ by 0.0091, resulting in a phase difference of fπ between them after transmission. The value of f (rounded off to two decimal places) and the state of polarization of the transmitted light is

Water from a tank is flowing down through a hole at its bottom with velocity 5 ms^-1. If this water falls on a flat surface kept below the hole at a distance of 0.1 m and spreads horizontally, the pressure (in kNm^-2) exerted on the flat surface is closest to
Given: acceleration due to gravity = 9.8 ms^-2 and density of water = 1000 kgm^-3

A particle (𝑝₁) of mass 𝑚 moving with speed 𝑣 collides with a stationary identical particle (𝑝₂). The particles bounce off each other elastically with 𝑝₁ getting deflected by an angle 𝜃 = 30° from its original direction. Then, which of the following statement(s) is/are true after the collision?

The absolute error in the value of sin𝜃 if approximated up to two terms in the Taylor’s series for 𝜃 = 60∘ is ___________ (rounded off to three decimal places).

A single pendulum hanging vertically in an elevator has a time period 𝑇₀ when the elevator is stationary. If the elevator moves upward with an acceleration of 𝑎 = 0.2𝑔, the time period of oscillations is 𝑇₁. Here 𝑔 is the acceleration due to gravity. The ratio\( \frac{𝑇_0}{ 𝑇_1}\) is (rounded off to two decimal places).

A rectangular pulse of width 0.5 cm is travelling to the right on a taut string (shown by full line in the figure) that has mass per unit length 𝜇1. The string is attached to another taut string (shown by dashed line) of mass per unit length 𝜇2. If the tension in both the strings is the same, and the transmitted pulse has width 0.7 cm, the ratio 𝜇1⁄𝜇2 is _______(rounded off to two decimal places)

An α particle with energy of 3 MeV is moving towards a nucleus of ⁵⁰Sn. Its minimum distance of approach to the nucleus is 𝑓×10⁻¹⁴ m. The value of 𝑓 is ________ (rounded off to one decimal place).

The lattice constant (in Å) of copper, which has FCC structure, is _________ (rounded off to two decimal places).
Given: density of copper is 8.91 g cm^-3 and its atomic mass is 63.55 g mol^-1 ; Avogadro’s number = 6.023 × 10²³ mol⁻¹

A rod of mass 𝑀, length 𝐿 and non-uniform mass per unit length \(λ(x)=\frac{3Mx^2}{L^3},\) is held horizontally by a pivot, as shown in the figure, and is free to move in the plane of the figure. For this rod, which of the following statements are true?

Unit vector normal to the equipotential surface of 𝑉(𝑥, 𝑦, 𝑧) =4𝑥²+𝑦² + 𝑧 at (1,2,1) is given by (𝑎𝑖̂+ 𝑏𝑗̂+ 𝑐𝑘̂). The value of |𝑏| is (rounded off to two decimal places).

The sum of the x-components of unit vectors 𝑟̂ ̇ and 𝜃̂̇ for a particle moving with angular speed 2 rad s ^-1 at angle 𝜃 = 215° is__________ (rounded off to two decimal places)

A spacecraft has speed 𝑣_𝑠=𝑓𝑐 with respect to the earth, where 𝑐 is the speed of light in vacuum. An observer in the spacecraft measures the time of one complete rotation of the earth to be 48 hours. The value of 𝑓 is (rounded off to two decimal places).

Consider a spring mass system with mass 0.5 kg and spring constant 𝑘 = 2 Nm^-1 in a viscous medium with drag coefficient 𝑏 = 3 kg s ^-1 . The additional mass required so that the motion becomes critically damped is _______ kg (rounded off to three decimal places)

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

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)