List of top Physics Questions

In a coil the current varies from \(-3\,A\) to \(+3\,A\) in \(4\,s\), and induces an emf of \(0.2\,V\). The self inductance of the coil is

To have dissipative power in an LCR series circuit to be half

Which of the following statements are correct about electromagnetic waves?

• Electromagnetic waves are produced by accelerating charges

• Electromagnetic waves do not transport charge

• Energy of electromagnetic waves is shared equally between electric and magnetic fields

• Electromagnetic waves travel with same speed in all media

Two electric charges \(+3.2\times10^{-19}\,\text{C}\) and \(-3.2\times10^{-19}\,\text{C}\) are placed \(2.4\,\text{\AA}\) apart to form an electric dipole. It is placed in a uniform electric field of intensity \(4\times10^5\,\text{V m}^{-1}\). The work done to rotate the electric dipole from equilibrium position by \(180^\circ\) is:

In the arrangement shown, the charge on capacitor \(C_1\) is: center

center

In the circuit given below, each of three resistors of \(4\Omega\) can have a maximum power of \(20\,\text{W}\) otherwise, it will melt. The maximum power which the whole circuit can take is: center

center

A circle of radius \(r\) is drawn in a uniform electric field \(E\) as shown in figure. If \(V_A, V_B, V_C\) and \(V_D\) are the potentials at \(A,B,C\) and \(D\) respectively, then: center

center

The current \(I\) drawn from the \(5\,\text{V}\) source will be: center

center

Assertion (A): When \(1\,g\) of ice melts at constant temperature at a pressure of \(1\,atm\), the increase in internal energy is greater than \(80\,cal\).
Reason (R): During melting of ice, work is done on the ice.

The temperature at which the rms speed of hydrogen molecules is equal to that of oxygen molecules at \(47^\circ C\) is

For a prism of angle \(5^\circ\), the angle of minimum deviation \((\delta)\) varies with refractive index \((\mu)\) as shown in the graph. The slope of the graph is: center

center

In Young’s double slit experiment, the ratio of intensities of maxima and minima is \(25:9\). The ratio of intensities of two slits is:

An object is placed at a distance of \(15\,\text{cm}\) from a convex lens of focal length \(10\,\text{cm}\). On the other side of the lens, at its focus, a convex mirror is placed such that final image formed coincides with the object. The focal length of convex mirror is:

A person at rest hears an electric siren which is stationary. Now the person accelerates at \(2\,\text{m s}^{-2}\) along a straight line path. The distance travelled by him when he hears the frequency of the siren as \(94\%\) of its original value is \((\text{speed of sound} = 330\,\text{m s}^{-1})\):

Three rods made of the same material and having the same cross-section have been joined as shown in figure. Each rod is of same length. The left and right ends are kept at \(0^\circ C\) and \(90^\circ C\) respectively. The temperature of the junction will be center

center

Two gases \(A\) and \(B\) are initially at same pressure, volume and temperature. If \(A\) is compressed isothermally and \(B\) adiabatically to half of the initial volume, then the final pressure of \(A\)

Heat energy released by water of mass \(3\,\text{kg}\) when it is cooled by \(20^\circ C\) is \((\text{specific heat capacity of water}=4200\,\text{J kg}^{-1}\text{K}^{-1})\)

A large tank filled with water to a height \(h\) is to be emptied through a small hole at the bottom. The ratio of times taken for the level of water to fall from \(h\) to \(\frac{h}{2}\) and from \(\frac{h}{2}\) to zero is

Work required to shift an artificial satellite from an orbit of radius \(r\) to an orbit of radius \(2r\) is

The elastic behavior of a material for linear stress to linear strain is given in the figure. The energy density for a linear strain of \(4\times10^{-4}\) is center

center

A force \(F=4x\) is applied to move an object from \(x=0\) to \(x=2\,m\), then the work done is:

On imparting an initial velocity \(v_0\), a ball begins to move in horizontal circle of radius \(R\) on horizontal plane. If the coefficient of friction between the ball and plane is \(\mu\), then the time required by ball to come to rest is: center

center

A \(5\,\text{kg}\) block pushed by \(100\,\text{N}\) over \(10\,\text{m}\) on a plane. If the coefficient of friction between the block and plane is \(0.2\), then the final kinetic energy of the block is _ _ _ (\(g=10\,\text{m s}^{-2}\)):

A thin wire of length \(L\) and uniform linear mass density \(\rho\) is bent into a circular loop with centre at \(O\) as shown. The moment of inertia of the loop about the axis \(XX'\) is: center

center

A particle is executing simple harmonic motion with time period \(T\) and amplitude \(A\). The distance travelled by the particle in \(\frac{T}{12}\) time starting from rest is: