A bob of mass ' \(m\) ' is suspended by a light string of length ' \(L\) '. It is imparted a minimum horizontal velocity at the lowest point \(A\) such that it just completes half circle reaching the top most position B. The ratio of kinetic energies \(\frac{(\text { K.E. })_A}{(\text { K.E. })_B}\) is _______.

Three identical charged balls each of charge \(2 \,C\) are suspended from a common point \(P\) by silk threads of \(2 \,m\) each (as shown in figure). They form an equilateral triangle of side \(1 \,m\). The ratio of net force on a charged ball to the force between any two charged balls will be ...........

Consider two solid spheres of radii \(\mathrm{R}_{1}=1 \;\mathrm{m}\) \(\mathrm{R}_{2}=2\; \mathrm{m}\) and masses \(\mathrm{M}_{1}\) and \(\mathrm{M}_{2},\) respectively. The gravitational field due to sphere \((1)\) and \((2)\) are shown. The value of \(\frac{\mathrm{M}_{1}}{\mathrm{M}_{2}}\) is

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Consider a ferromagnetic material :
Assertion (A) : The individual atoms in a ferromagnetic material possess a magnetic dipole moment and interact with one another in such a way that they spontaneously align themselves forming domains.
Reason (R) : At high enough temperature, the domain structure of ferromagnetic material disintegrates. Thus, magnetization will disappear at high enough temperature known as Curie temperature.
In the light of the above statements, choose the correct answer from the options given below :

A plane electromagnetic wave with frequency of \(30 {MHz}\) travels in free space. At particular point in space and time, electric field is \(6 {V} / {m}\). The magnetic field at this point will be \({x} \times 10^{-8} {T}\). The value of \({x}\) is ..... .

A series LCR circuit with \(R = 20\ \Omega\), \(L = 1.6\text{ H}\) and \(C = 40\ \mu\text{F}\) is connected to a variable frequency a.c. source. The inductive reactance at resonant frequency is _______ \(\Omega\).

\(AC\) voltage \(V(t)=20\,sin\omega \,t\) of frequency \(50\, {Hz}\) is applied to a parallel plate capacitor. The separation between the plates is \(2\, {mm}\) and the area is \(1 \,{m}^{2}\). The amplitude of the oscillating displacement current for the applied \(AC\) voltage is ...... \(\mu {A}\). [Take \(\left.\varepsilon_{0}=8.85 \times 10^{-12} \,{F} / {m}\right]\)

The output of the given circuit diagram is _______.

Two metal spheres of radius \(R\) and \(3 R\) have same surface charge density \(\sigma\). If they are brought in contact and then separated, the surface charge density on smaller and bigger sphere becomes \(\sigma_1\) and \(\sigma_2\), respectively. The ratio \(\frac{\sigma_1}{\sigma_2}\) is ________.

Identify the operation performed by the circuit given below

Two point charges \(Q\) each are placed at a distance \(d\) apart. A third point charge \(q\) is placed at a distance \(x\) from mid-point on the perpendicular bisector. The value of \(x\) at which charge \(q\) will experience the maximum \(Coulomb's force\) is ...............