Question Bank Directory

Two insulated charged copper spheres A and B have their centers separated by a distance of 50 cm. What is the mutual force of electrostatic repulsion if the charge on each is $6.5 \times 10^{-7}$ C? (The radii of A and B are negligible compared to the distance of separation.)

A body is thrown vertically upwards. If the air resistance is to be taken into account, then the time during which the body rises is:

In Young's double-slit experiment, if the separation between coherent sources is halved and the distance of the screen from the coherent sources is doubled, then the fringe width becomes:

Arrange the elements Li, Be, B, C, and N in increasing order of their first ionization enthalpies:

A hollow metal sphere of radius R is uniformly charged. The electric field due to the sphere at a distance r from the centre:

A string of length $l$ is fixed at both ends and is vibrating in second harmonic. The amplitude at antinode is $2\text{ mm}$. The amplitude of a particle at a distance $l/8$ from the fixed end is:

The angular width of the central maximum in the Fraunhofer diffraction for $\lambda = 6000 \text{ \AA}$ is $\theta_0$. When the same slit is illuminated by another monochromatic light, the angular width decreases by $30\%$. The wavelength of this light is:

The magnetic flux linked to a circular coil of radius R is given by: $\phi = 2t^3 + 4t^2 + 2t + 5$ Wb. What is the magnitude of the induced EMF in the coil at $t = 5$ s?

A source of sound S emitting waves of frequency $100 \text{ Hz}$ and an observer O are located at some distance from each other. The source is moving with a speed of $19.4 \text{ ms}^{-1}$ at an angle of $60^\circ$ with the source-observer line as shown in the figure. The observer is at rest. The apparent frequency observed by the observer (velocity of sound in air $330 \text{ ms}^{-1}$), is:

In the Young's double-slit experiment, the intensity of light at a point on the screen (where the path difference is $\lambda$) is $K$, where $\lambda$ is the wavelength of light used. The intensity at a point where the path difference is $\lambda/4$ will be

The correct order of first ionization enthalpy for the given four elements is:

For a transparent medium, relative permeability and permittivity, $\mu_r$ and $\varepsilon_r$ are 1.0 and 1.44 respectively. The velocity of light in this medium would be:

An unpolarised light beam strikes a glass surface at Brewster's angle. Then:

Twenty seven drops of same size are charged at $200 \text{ V}$ each. They combine to form a bigger drop. Calculate the potential of the bigger drop.

The equation of state of some gases can be expressed as (P + a/V²)(V − b) = RT. Here P is the pressure, V is the volume, T is the absolute temperature and a, b, R are constants. The dimensions of ‘a’ are:

A linearly polarized monochromatic light of intensity 10 lumen is incident on a polarizer. The angle between the direction of polarization of the light and that of the polarizer such that the intensity of output light is 2.5 lumen is:

A student measured the diameter of a small steel ball using a screw gauge of least count $0.001\text{ cm}$. The main scale reading is $5\text{ mm}$ and zero of circular scale division coincides with $25$ divisions above the reference level. If the screw gauge has a zero error of $-0.004\text{ cm}$, the correct diameter of the ball is:

A wave in a string has an amplitude of $2 \text{ cm}$. The wave travels in the positive direction of the x-axis with a speed of $128 \text{ m/s}$ and it is noted that $5$ complete waves fit in the $4 \text{ m}$ length of the string. The equation describing the wave is:

The major product (P) formed in the following reaction sequence is: [Reaction Scheme Missing]

A beam of light of $600\text{ nm}$ from a distant source falls on a single slit $1\text{ mm}$ wide and the resulting diffraction pattern is observed on a screen $2\text{ m}$ away. The distance between first dark fringes on either side of the central bright fringe is