Question Bank Directory

A positively charged particle +q is projected with speed v toward a fixed charge +Q, and rebounds after reaching a minimum distance r. What will be the new closest distance of approach if its initial velocity is doubled to 2v?

Three concentric spherical shells have radii a, b and c (a < b < c) and have surface charge densities σ, -σ and σ respectively. If V_A, V_B and V_C denote the potential of the three shells, if c = a + b, we have

The equivalent capacitance of the system shown in the following circuit is:

Two spherical bodies of masses M and 5M and radii R and 2R are released in free space with initial separation between their centres equal to 12R. If they attract each other due to gravitational force only, then the distance covered by the smaller body before collision is:

The escape velocity of a body on the earth's surface is $11.2 \text{ km/s}$. If the same body is projected upward with a velocity $22.4 \text{ km/s}$, the velocity of this body at an infinite distance from the centre of the earth will be:

A body projected vertically from the earth reaches a height equal to earth’s radius before returning to the earth. The power exerted by the gravitational force:

An increase in the temperature of a gas-filled container would lead to:

A particle of mass $m$ is projected with a velocity, $v = kv_e$ ($k < 1$) from the surface of the earth. The maximum height, above the surface, reached by the particle is: (Where $v_e = $ escape velocity, $R = $ the radius of the earth)

An electric dipole is placed as shown in the figure. The electric potential (in 10² V) at the point P due to the dipole is: (ε₀ = permittivity of free space and 1/4πε₀ = k)

A satellite is orbiting just above the surface of the earth with period $T$. If $d$ is the density of the earth and $G$ is the universal constant of gravitation, the quantity $\frac{3\pi}{Gd}$ represents:

Which of the following hormones are secreted in women only during pregnancy? (a) Estrogen (b) Progesterone (c) Human chorionic gonadotropin (hCG) (d) Human placental lactogen (hPL) (e) Relaxin

The molecular weight of two gases is $M_1$ and $M_2$. At any temperature, the ratio of root mean square velocities $v_1$ and $v_2$ will be:

Assuming the earth to be a sphere of uniform density, its acceleration due to gravity acting on a body:

Which one of the following plots represent the variation of gravitational field on a particle at distance $r$, due to a thin spherical shell of radius $R$? ($r$ is measured from the centre of the spherical shell).

Two charged spherical conductors of radii $R_1$ and $R_2$ are connected by a wire. The ratio of surface charge densities of spheres $(\sigma_1/\sigma_2)$ is:

Assuming that the gravitational potential energy of an object at infinity is zero, the change in potential energy (final - initial) of an object of mass $m$ when taken to a height $h$ from the surface of the earth (of radius $R$ and mass $M$), is given by:

The ratio of frequencies of fundamental harmonic produced by an open pipe to that of closed pipe having the same length is:

In a gravitational field, the gravitational potential is given by $V=-\frac{K}{x}$ J/kg. The gravitational field intensity at the point $(2,0,3)$ m is:

Two satellites of Earth, $S_1$ and $S_2$, are moving in the same orbit. The mass of $S_1$ is four times the mass of $S_2$. Which one of the following statements is true?

Ovulation in the human female normally takes place during which phase of the menstrual cycle: