List of top Physics Questions

A metallic sphere of diameter 2mm and density 10.5 g/cc is dropped in glycerine having viscosity 10 poise and density 1.5 g/cc. The terminal velocity attained by sphere is ______ cm/s. [\(\pi = \frac{22}{7}, g = 10 \text{ m/s}^2\)]
On two metal surfaces, a monochromatic light of $6 \text{ eV}$ was incident. They have ratio of their work function and maximum KE as $\frac{\Phi_1}{\Phi_2} = \frac{1}{2}$ and $\frac{(KE_{\max})_1}{(KE_{\max})_2} = \frac{2.62}{1}$. Then $\Phi_1$ and $\Phi_2$ values are respectively (in $\text{eV}$).
A particle is projected from bottom of inclined plane with speed u find distance covered along plane before coming to rest :
Two beads P & Q move along two wires straight and semi circle. At some instant both are shown in figure having same horizontal component of velocity V. Find relation of time taken to reach A by beads :
A bomb at rest explodes into three pieces in the ratio of masses 2 : 2 : 3. The identical masses fly off perpendicular to each other with 18 m/s. Find speed of the third piece.
Which of the following is an isobaric pair :
A parachutist jumps from a helicopter. It falls freely for 2 sec. Then he opens parachute which produces retardation of 3 m/s\(^2\). When his height from ground is 10 m his velocity is 5 m/s. Find his initial height from ground.
An \( \alpha \)-particle of energy \(8\,\text{MeV}\) is directed towards a fixed copper nucleus \((Z = 29)\). Calculate the distance of closest approach.
Radiation containing frequencies \(6 \times 10^{14}\,\text{Hz}\) and \(9 \times 10^{14}\,\text{Hz}\) falls on a metal surface with work function \(2.5\,\text{eV}\). Calculate the maximum energy of emitted electrons (in eV).
A closed tube filled with ideal gas is rotating with angular speed \(\omega\) about an axis passing through end \(A\). Find the pressure at the other end \(B\). (\(M\) is the molar mass of the gas, \(\ell\) is the length of the tube and \(T\) is the temperature of the gas.) Given pressure at \(A\) is \(P_A\).
Find the moment of inertia about the given axis. Two solid spheres are arranged as shown. Given: \[ m_1 = 10\,\text{kg},\; R_1 = 20\,\text{cm}; \qquad m_2 = 5\,\text{kg},\; R_2 = 10\,\text{cm} \]
Match the columns:
Choose the correct option.
If electric field of EM wave is given by $60[\sin(3 \times 10^{14} t) + \sin(12 \times 10^{14} t)]$ at $x = 0$, falls on a photosensitive material having work function $2.8$ eV. Find the maximum energy (in eV) of ejected electrons.
In the figure the LED will glow for input \(A,B,C,D\) (\(0\) is low potential and \(1\) is high potential).
Statement--1: Liquid pressure is only exerted on solid surfaces in contact and is exerted in between the layers of liquid. Statement--2: Surface tension arises due to difference in potential energy of molecules in the bulk of liquid and at the surface.
The energy required to excite an electron from the first Bohr orbit of a hydrogen atom to the second Bohr orbit is:
A photon is incident on a particle having mass \(m = 15.356\,\text{amu}\). What should be the frequency of the photon so that the particle of mass \(m\) breaks into four \(\alpha\)-particles? (Given: \(m_\alpha = 4.004\,\text{amu}\); \(h = 6.6\times10^{-34}\,\text{J s}\))
Match the following:
Choose the correct option:
An \(\alpha\)-particle is projected towards a fixed gold nucleus (\(Z=79\)) with kinetic energy \(7.9\,\text{MeV}\). If the particle is just able to touch the nuclear boundary, find the diameter of the nucleus.
Two discs have the same moment of inertia about their axes. Their thicknesses are \(t_1\) and \(t_2\) and they have the same density. If \( \dfrac{R_1}{R_2} = \dfrac{1}{2} \), then find \( \dfrac{t_1}{t_2} \).
An ideal solenoid is kept with its axis vertical. A current \( I_0 \) is flowing in the solenoid. A charge \( q \) is thrown vertically downward inside the solenoid. The acceleration of the charged particle is:
Two mechanical waves travel on strings of equal length \(L\) and equal tension \(T\). The linear mass densities of the strings are in the ratio \(\dfrac{\mu_1}{\mu_2} = \dfrac{1}{2}\). Find the ratio of time taken for a wave pulse to travel from one end to the other in both strings. (Neglect gravity).
Considering the case of magnetic field produced by air-filled current carrying solenoid, show that the magnetic energy density of a magnetic field \( B \) is \( \frac{B^2}{2\mu_0} \).
Three batteries E1, E2, and E3 of emfs and internal resistances (4 V, 2 \(\Omega\)), (2 V, 4 \(\Omega\)) and (6 V, 2 \(\Omega\)) respectively are connected as shown in the figure. Find the values of the currents passing through batteries E1, E2, and E3.
Three batteries E1, E2, and E3 of emfs and internal resistances
Two wires made of the same material have the same length \( l \) but different cross-sectional areas \( A_1 \) and \( A_2 \). They are connected together with a cell of voltage \( V \). Find the ratio of the drift velocities of free electrons in the two wires when they are joined in: (i) series, and (ii) parallel.