Physics

Two identical conducting spheres with negligible volume have 2.1 nC and 0.1 nC charges, respectively. They are brought into contact and then separated by a distance of 0.5m. The electrostatic force acting between the spheres is …………….* 10^-9N.

$\left[Given:4\pi {\epsilon }_0=\frac{1}{9*10^9}SIunit\right]$

If $\overrightarrow{P}*\overrightarrow{Q}=\overrightarrow{Q}*\overrightarrow{P},$ the angle between $\overrightarrow{P}and\overrightarrow{Q}is\theta \left(0°<\theta <360°\right).$ The value of 'θ' will be………

The initial velocity vi required to project a body vertically upward from the surface of the earth to reach a height of 10R, where R is the radius of the earth, may be described in terms of escape velocity v_e such that $v_i=\sqrt[]{\frac{x}{y}}*v_e.$ The value of x will be………

The wavelength of an X-ray beam is $10\stackrel{o}{A}.$ The mass of a fictitious particle having the same energy as that of the X-ray photons is $\frac{x}{3}hkg.$ The value of x is………. (h = Planck's constant)

The percentage increase in the speed of transverse waves produced in a  stretched string if the tension is increased by 4%, will be………….%.

A current of 6 A enters one corner P of an equilateral triangle PQR having 3 wires of resistance $2\Omega$  each and leaves by the corner R. The currents i₁ in ampere is………

A reversible heat engine converts one-fourth of the heat input into work. When the temperature of the sink is reduced by 52K, its efficiency is doubled. The temperature is Kelvin of the source will be…………

Two particles having masses 4g and 16g respectively are moving with equal kinetic energies. The ratio of the magnitudes of their linear momentum is n : 2. The value of n will be……….

Two small spheres each of mass 10mg are suspended from a point by threads 0.5m long. They are equally charged and repel each other to a distance of 0.20m. The charge on each of the sphere is $\frac{a}{21}*10^{-8}C.$  The value of 'a' will be……. [Given g = 10 ms^-2]

Two identical springs of spring constant '2k' are attached to a block of mass m and to fixed support (see figure). When the mass is displaced from equilibrium position on either side, it executes simple harmonic motion. The time period of oscillations of this system is