List of top Physics Questions

A mass $M$ is suspended from a light spring. An additional mass $m$ added displaces the spring further by a distance $X$. Now the combined mass will oscillate on the spring with period
A particle $A$ has charge $+q$ and particle $B$ has charge $+4q$, each of them having the same mass $m$. When allowed to fall from rest through the same? electrical potential difference, the ratio of their speeds will become
A concave mirror gives an image three times as large as its object placed at a distance of $20\, cm$ from it. For the image to be real, the focal length should be
The average energy of molecules in a sample of oxgen gas at $ {300 \, K}$ are $ {6.21 \times 10^{-21} \, J}$. The corresponding values at $ {600\, K}$ are
A nuclear fission is said to be critical when multiplication factor or $K$
A crane with.a steel cable of length $ {11 \,m}$ and radius $ {2.0\, cm}$ is employed to lift a block of concrete of mass 40 tons in a building site. If the Young's Modulus of steel is $ {2.0 \times 10^{11} \, Pa}$, what will be roughly the increase in the length of the cable while lifting the block? (Take $ {g = 10\, ms^{-2}}$)
The diagram shows a barrel of weight $ {1.0 \times 10^{3} \,N}$ on a frictionless slope inclined at $30?$ to the horizontal. The force -is parallel to the slope. What is the work done in moving the barrel a distance of $5.0 \,m$ up the slope?
The instantaneous voltage of a $50\,Hz$ generator giving peak voltage as $300\,V$. The generator equation for this voltage is
Two resistances $A$ and $B$ have colour codes orange, blue, white and brown, red, green respectively. Then ratio of their resistances $A : B$ is
A ship A is moving Westwards with a speed of 10 km $h^{ - 1}$ and a ship B 100 km South of A, is moving Northwards with a speed of 10 km $ h^{ - 1}$. The time after which the distance between them becomes shortest, is
A particle of unit mass undergoes one dimensional motion such that its velocity varies according to $v(x)=\beta x^{-2n},$ where $\beta$ and $n$ are constants and $x$ is the position of the particle. The acceleration of the particle as a function of $x$, is given by
A proton and an alpha particle both enter a region of uniform magnetic field $B$, moving at right angles to the field $B$. If the radius of circular orbits for both the particles is equal and the kinetic energy acquired by proton is $1\,MeV$, the energy acquired by the alpha particle will be
A parallel plate air capacitor of capacitance C is connected to a cell of emf V and then disconnected from it. A dielectric slab of dielectric constant K, which can just fill the air gap of the capacitor, is now inserted in it. Which of the following is incorrect?
A mass m moves in a circle on a smooth horizontal plane with velocity $ v_0 $ at a radius $ R_0. $ The mass is attached to a string which passes through a smooth hole in the plane as shown. The tension in the string is increased gradually and finally m moves in a circle of radius $ \frac{R_0}{2}. $ The final value of the kinetic energy is
An ideal gas is compressed to half its initial volume by means of several processes. Which of the process results in the maximum work done on the gas?
A wire carrying current I has the shape as shown in adjoining figure. Linear parts of the wire are very long and parallel to . X-axis while semicircular portion of radius R is lying in Y-Z plane. Magnetic field at point O is
A parallel plate air capacitor has capacity $C$, distance of separation between plates is $d$ and potential difference $V$ is applied between the plates. Force of attraction between the plates of the parallel plate air capacitor is
Consider $3^{rd}$ orbit of $He^+$ (Helium), using non-relativistic approach, the speed of electron in this orbit will be [given $ K= 9 \times 10^9$ constant, Z = 2 and h (Planck's Constant) = $6.6 \times 10^{-34} J s$]
Two metal wires of identical dimensions are connected in series. If $\sigma_1$ and $\sigma_2$ are the conductivities of the metal wires respectively, the effective conductivity of the combination is
A block A of mass $m_1$ rests on a horizontal table. A light string connected to it passes over a frictionless pully at the edge of table and from its other end another block B of mass $m_2$ is suspended. The coefficient of kinetic friction between the block and the table is $\mu_k$. When the block A is sliding on the table, the tension in the string is
A resistance 'R' draws power 'P' when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance of the circuit becomes 'Z', the power drawn will be
A circuit contains an ammeter, a battery of $30\, V$ and a resistance $40.8\, ohm$ all connected in series. If the ammeter has a coil of resistance $480\, ohm$ and a shunt of $20\, ohm$, the reading in the ammeter will be
A potentiometer wire of length $L$ and a resistance $r$ are connected in series with a battery of e.m.f. $E_0$ and a resistance $r_1$ An unknown e.m.f. $E$ is balanced at a length $l$ of the potentiometer wire. The e.m.f. $E$ will be given by
An electron moves on a straight line path $XY$ as shown. The abcd is a coil adjacent to the path of electron. What will be the direction of current, if any, induced in the coil?
The dimension of magnetic flux is