List of practice Questions

Identify the function which represents a periodic motion

The capacitance of a parallel plate capacitor with air as medium is $6\, \mu F$. With the introduction of a dielectric medium, the capacitance becomes 30 $\mu F.$ The permittivity of the medium is : $(\epsilon_0 = 8.85 \times 10^{-12} C^2N^{-1}m^{-2}$)

The color code of a resistance is given below : The values of resistance and tolerance, respectively, are :

The correct option for free expansion of an ideal gas under adiabatic condition is :

The number of protons, neutrons and electrons in $^{175}_{71} Lu,$ respectively , are :

The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is : (c = speed of electromagnetic waves)

Two particles of mass $5\,kg$ and $10\,kg$ respectively are attached to the two ends of a rigid rod of length 1m with negligible mass. The centre of mass of the system from the $5\,kg$ particle is nearly at a distance of :

When a uranium isotope $^{235}_92 U$ is bombarded with a neutron, it generates $^{89}_{36} Kr$, three neutrons and :

The solids which have negative temperature coefficient of resistance are :

A screw gauge has least count of 0.01 mm and there are 50 divisions in its circular scale. The pitch of the screw gauge is:

Light with an average flux of $20\,\Omega/cm^2$ falls on a non-reflecting surface at normal incidence having surface area $20\,cm^2$. The energy received by the surface during time span of $1\,minute$ is :

A spherical conductor of radius 10 cm has a charge of \(3.2 \times 10^{-7} C\) distributed uniformly. What is the magnitude of electric field at a point \(15\,cm\) from the centre of the sphere?
\((\frac {1}{4\pi \epsilon_o} = 9 \times 10^9 Nm^2/C^2)\)

The increase in the width of the depletion region in a p-n junction diode is due to :

An electron is accelerated from rest through a potential difference of V volt. If the de Broglie wavelength of the electron is $1.227 \times 10^{-2}nm$, the potential difference is :

An iron rod of susceptibility 599 is subjected to a magnetising field of 1200 A $m^{-1}$. The permeability of the material of the rod is : $(\mu_o = 4\pi \times 10^{-7} T\,m\,A^{-1})$

Dimensions of stress are:

For transistor action, which of the following statements is correct ?

Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled?

For the logic circuit shown, the truth table is :

Which of the following graph represents the variation of resistivity $(\rho)$ with temperature (T) for copper ?

A wheel with $20$ metallic spokes each $1\, m$ long is rotated with a speed of $120\, rpm$ in a plane perpendicular to a magnetic field of $0.4\, G$. The induced emf between the axle and rim of the wheel will be, $(1 G = 10^{-4}\, T)$

A wire of length L, area of cross section A is hanging from a fixed support. The length of the wire changes to \(L_1\) when mass M is suspended from its free end. The expression for Young’s modulus is:

A wire of length $L$ metre carrying a current of $I$ ampere is bent in the form of a circle. Its magnetic moment is,

The angle of $1'$ (minute of arc) in radian is nearly equal to

Three identical spheres, each of mass $M$, are placed at the corners of a right angle triangle with mutually perpendicular sides equal to $2\,m$ (see figure). Taking the point of intersection of the two mutually perpendicular sides as the origin, find the position vector of centre of mass