List of top Physics Questions on General Physics asked in JEE Main

A small block of mass \(m\) slides down from the top of a frictionless inclined surface, while the inclined plane is moving towards left with constant acceleration \(a_0\). The angle between the inclined plane and ground is \(\theta\) and its base length is \(L\). Assuming that initially the small block is at the top of the inclined plane, the time it takes to reach the lowest point of the inclined plane is _______. 

Which one of the following is not a measurable quantity?
Identify the correct statements:
[A.] Electrostatic field lines form closed loops.
[B.] The electric field lines point radially outward when charge is greater than zero.
[C.] The Gauss’s Law is valid only for inverse-square force.
[D.] The work done in moving a charged particle in a static electric field around a closed path is zero.
[E.] The motion of a particle under Coulomb’s force must take place in a plane.
Choose the correct answer from the options given below:
The speed of a longitudinal wave in a metallic bar is \(400\,\text{m/s}\). If the density and Young’s modulus of the bar material increase by \(0.5%\) and \(1%\) respectively, then the speed of the wave is changed approximately to _______ m/s.
The mean free path of a molecule of diameter \(5\times10^{-10}\,\text{m}\) at temperature \(41^\circ\text{C}\) and pressure \(1.38\times10^5\,\text{Pa}\) is given as _______ m. (Given \(k_B=1.38\times10^{-23}\,\text{J/K}\))
A nucleus has mass number \(\alpha\) and radius \(R_\alpha\). Another nucleus has mass number \(\beta\) and radius \(R_\beta\). If \(\beta=8\alpha\), then \(R_\alpha/R_\beta\) is:
In an experiment, a set of readings are obtained as follows: \[ 1.24~\text{mm},\ 1.25~\text{mm},\ 1.23~\text{mm},\ 1.21~\text{mm}. \] The expected least count of the instrument used in recording these readings is _______ mm.
Number of photons of equal energy emitted per second by a 6 mW laser source
operating at wavelength 663 nm is _______.

(Given: h = 6.63 × 10^-34 J·s and c = 3 × 10^8 m/s)
A particle starts moving from time \(t=0\) and its coordinate is given as \[ x(t)=4t^3-3t. \] Consider the following statements:
[A.] The particle returns to its original position (origin) \(0.866\) units later.
[B.] The particle is \(1\) unit away from origin at its turning point.
[C.] Acceleration of the particle is non-negative.
[D.] The particle is \(0.5\) units away from origin at its turning point.
[E.] The particle never turns back as acceleration is non-negative.
Choose the correct answer from the options given below:

Match List–I with List–II.

List–I                                       List–II
A. Coefficient of viscosity       I. [ M L^-1 T^-2 ]
B. Surface tension                  II. [ M L^-2 T^-2 ]
C. Pressure                             III. [ M L^0 T^-2 ]
D. Surface energy                  IV. [ M L^-1 T^-1 ]

Choose the correct answer from the options given below:

When the position vector \[ \vec r = x\hat{i}+y\hat{j}+z\hat{k} \] changes sign as \(\vec r \rightarrow -\vec r\), which one of the following vectors will {not flip under sign change?}

As shown in the figure, a spring is kept in a stretched position with some extension by holding the masses \(1\,\text{kg}\) and \(0.2\,\text{kg}\) with a separation more than spring natural length and then released. Assuming the horizontal surface to be frictionless, the angular frequency (in SI unit) of the system is _______. (Given \(k=150\,\text{N/m}\)) 

A flywheel having mass \(3\,\text{kg}\) and radius \(5\,\text{m}\) is free to rotate about a horizontal axis. A string having negligible mass is wound around the wheel and the loose end of the string is connected to a \(3\,\text{kg}\) mass. The mass is kept initially and released. Kinetic energy of the flywheel when the mass descends by \(3\,\text{m}\) is _______ J. \((g=10\,\text{m s}^{-2})\) Given: \[ M = 3\,\text{kg}, \quad R = 5\,\text{m}, \quad m = 3\,\text{kg}, \quad h = 3\,\text{m}, \quad g = 10\,\text{m s}^{-2} \]
Two tuning forks \(A\) and \(B\) are sounded together giving rise to 8 beats in 2 s. When fork \(A\) is loaded with wax, the beat frequency is reduced to 4 beats in 2 s. If the original frequency of tuning fork \(B\) is \(380\ \text{Hz}\), find the original frequency of tuning fork \(A\). Given: \[ f_B = 380\ \text{Hz} \]
A beam of light consisting of wavelengths \(650\,\text{nm}\) and \(550\,\text{nm}\) illuminates Young’s double slits with separation \(d=2\,\text{mm}\) such that the interference fringes are formed on a screen placed at a distance \(D=1.2\,\text{m}\) from the slits. The least distance from the central maximum, where the bright fringes due to both wavelengths coincide, is ________ \(\times10^{-5}\,\text{m}\). Given: \[ \lambda_1=650\,\text{nm},\quad \lambda_2=550\,\text{nm},\quad d=2\times10^{-3}\,\text{m},\quad D=1.2\,\text{m} \]

A thermodynamic system is taken through the cyclic process \(ABC\) as shown in the \(P\!-\!V\) diagram. The total work done by the system during the cycle \(ABC\) is _______ J. 

Given: The area enclosed by the cycle in the \(P\!-\!V\) diagram represents the work done.