List of top Questions asked in AP EAPCET

The half-life of a certain radio isotope is \(4\) minutes. The number of radioactive nuclei at a given instant is \(10^6\). Then the number of radioactive nuclei left \(2\) minutes later would be

Light of wavelength \(1000\AA\) incidents on a metal surface of work function \(6\,eV\). The maximum kinetic energy of photoelectrons is

A ball has a mass of \(50\,\text{g}\) and a speed of \(50\,\text{m s}^{-1}\). If the speed is measured within an accuracy of \(2\%\), then the uncertainty in its position (in m) is
\[ (h = 6.626 \times 10^{-34}\,\text{J s}, \ \pi = 3.14) \]

If a current is passing in a spring, it

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

Magnetic moment of an electron moving in a circular orbit of radius \(r\) with a speed \(v\) is

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

A material satisfies the relation \(\mu_0(H+M)=0\), where \(H\) and \(M\) are magnetic intensity and magnetization respectively; then the material is

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

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

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

center

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

center

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:

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

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.

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 \((\text{speed of sound} = 330\,\text{m s}^{-1})\):

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

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

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

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 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