A block is fastened to a horizontal spring. The block is pulled to a distance \(x =10\,cm\) from its equilibrium position (at \(x =0\) ) on a frictionless surface from rest. The energy of the block at \(x =5\) \(cm\) is \(0.25\,J\). The spring constant of the spring is \(.........Nm ^{-1}\)

Given below are two statements: one is labelled as Assertion \(A\) and the other is labelled as Reason \(R\). Assertion \(A\) : The photoelectric effect does not take place, if the energy of the incident radiation is less than the work function of a metal. Reason \(R\) : Kinetic energy of the photoelectrons is zero, if the energy of the incident radiation is equal to the work function of a metal. In the light of the above statements, choose the most appropriate answer from the options given below

Conductor wire ABCDE with each \(\operatorname{arm} 10 \mathrm{~cm}\) in length is placed in magnetic field of \(\frac{1}{\sqrt{2}}\) Tesla, perpendicular to its plane. When conductor is pulled towards right with constant velocity of \(10 \mathrm{~cm} / \mathrm{s}\), induced emf between points A and E is _____ mV.

Given below are two statements: one is labelled as Assertion\((A)\) and the other is labelled as Reason \((R).\) \(Assertion\) \((A)\) : In Vernier calliper if positive zero error exists, then while taking measurements, the reading taken will be more than the actual reading. \(Reason\) \((R)\) : The zero error in Vernier Calliper might have happened due to manufacturing defect or due to rough handling. In the light of the above statements, choose the correct answer from the options given below :

The radius of curvature of each surface of a convex lens having refractive index \(1.8\) is \(20\,cm\). The lens is now immersed in a liquid of refractive index \(1.5\). The ratio of power of lens in air to its power in the liquid will be \(x : 1\). The value of \(x\) is \(.....\)

The dimensions of angular momentum , latent heat and capacitance are, respectively.

A \(70\, kg\) man leaps vertically into the air from a crouching position. To take the leap the man pushes the ground with a constant force \(F\) to raise himself The center of gravity rises by \(0.5\, m\) before he leaps. After the leap the \(c.g.\) rises by another \(1\, m\). The maximum power delivered by the muscles is : (Take \(g\, = 10\, ms^{-2}\))

Consider a circular loop that is uniformly charged and has a radius \(\mathrm{a} \sqrt{2}\). Find the position along the positive z -axis of the cartesian coordinate system where the electric field is maximum if the ring was assumed to be placed in xy-plane at the origin :

If \(\overrightarrow{ A }=(2 \hat{ i }+3 \hat{ j }-\hat{ k }) \;m\) and \(\overrightarrow{ B }=(\hat{ i }+2 \hat{ j }+2 \hat{ k })\; m\). The magnitude of component of vector \(\overrightarrow{ A }\) along vector \(\vec{B}\) will be \(......m\).

Two discs have moments of intertia \({I}_{1}\) and \({I}_{2}\) about their respective axes perpendicular to the plane and passing through the centre. They are rotating with angular speeds, \(\omega_{1}\) and \(\omega_{2}\) respectively and are brought into contact face to face with their axes of rotation coaxial. The loss in kinetic energy of the system in the process is given by :

Two tubes of radii \(r_1\) and \(r_2\), and lengths \(l_1\) and \(l_2\), respectively, are connected in series and a liquid flows through each of them in streamline conditions. \(P_1\) and \(P_2\) are pressure differences across the two tubes. If \(P_2\) is \(4P_1\) and \(l_2\) is \( \frac{l_1}{4}\) , then the radius \(r_2\) will be equal to

The give graph shown variation (with distance \(r\) from centre) of