KCET 2020

The electric field lines on the left have twice the separation on those on the right as shown in figure. If the magnitude of the field at \(A\) is \(40 \mathrm{~Vm}^{-1}\), what is the force on \(20 \mu \mathrm{C}\) charge kept at \(B\) ?

Iceberg floats in water with part of it submerged. What is the fraction of the volume of iceberg submerged, if the density of ice is \(\rho_i=0.917 \mathrm{~g} \mathrm{~cm}^{-3}\) ?

The value of acceleration due to gravity at a height of \(10 \mathrm{~km}\) from the surface of earth is \(x\). At what depth inside the earth is the value of the acceleration due to gravity has the same value \(x\) ?

A sphere, a cube and a thin circular plate all of same material and same mass initially heated to same high temperature are allowed to cool down under similar conditions. Then, the

A certain amount of heat energy is supplied to a monoatomic ideal gas which expands at constant pressure. What fraction of the heat energy is converted into work?

In an adiabatic expansion of an ideal gas the product of pressure and volume

A paramagnetic sample shows a net magnetisation of \(8 \mathrm{Am}^{-1}\) when placed in an external magnetic field of \(0.6 \mathrm{~T}\) at a temperature of \(4 \mathrm{~K}\). When the same sample is placed in an external magnetic field o...

In a permanent magnet at room temperature

Rain is falling vertically with a speed of \(12 \mathrm{~ms}^{-1}\). A woman rides a bicycles with a speed of \(12 \mathrm{~ms}^{-1}\) in east to west direction. What is the direction in which she should hold her umbrella?

At a metro station, a girl walks up a stationary escalator in \(20 \mathrm{~s}\). If she remains stationary on the escalator, then the escalator take her up in \(30 \mathrm{~s}\). The time taken by her to walk up on the moving escalator wil...

A cyclotron is used to accelerate protons \(\left({ }_1^l \mathrm{H}\right)\) deuterons \(\left({ }_1^2 \mathrm{H}\right)\) and \(\alpha\)-particles \(\left({ }_2^4 \mathrm{He}\right)\). While exiting under similar conditions, the minimum $...

The magnetic field at the origin due to a current element \(i d \mathbf{l}\) placed at a point with vector position \(\mathrm{r}\) is

The ratio of magnetic field at the centre of a current carrying circular coil to its magnetic moment is \(x\), if the current and the radius both are doubled. The new ratio will become

In the given figure, the magnetic field at \(O\).

A long cylindrical wire of radius \(R\) carries a uniform current \(I\) flowing through it. The variation of magnetic field with distance \(r\) from the axis of the wire is shown by

Two long straight parallel wires are a distance \(d\) part. They carry steady equal currents flowing out of the plane of the paper. The variation of magnetic field $B$ along the line \(x x^{\prime}\) is given by

An object approaches a convergent lens from the left of the lens with a uniform speed \(5 \mathrm{~m} / \mathrm{s}\) and stops at the focus, the image

The refracting angle of prism is \(A\) and refractive index of material of prism is \(\cot \frac{A}{2}\). The angle of minimum deviation is \(A\)

The following figure shows a beam of light converging at point \(P\). When a concave lens of focal length \(16 \mathrm{~cm}\) is introduced in the path of the beam at a place shown by dotted line such that \(O P\) becomes the axis of the le...

A wheel starting from rest gains an angular velocity of \(10 \mathrm{~rad} / \mathrm{s}\) after uniformly accelerated for \(5 \mathrm{~s}\). The total angle through which it has turned is

A thin uniform rectangular plate of mass \(2 \mathrm{~kg}\) is placed in \(x y\)-plane as shown in figure. The moment of inertial about \(x\)-axis is \(I_x=0.2 \mathrm{~kgm}^2\) and the moment of inertia about \(Y\)-axis is $$I_y=0.3 \mathr...

A positive hole in a semiconductor is

In the following circuit what are P and Q

A tray of mass \(12 \mathrm{~kg}\) is supported by two identical springs as shown in figure. When the tray is pressed down slightly and then released, it executes SHM with a time period of \(1.5 \mathrm{~s}\). The spring constant of each sp...

A cylindrical wire has a mass \((0.3 \pm 0.003) \mathrm{g}\), radius \((0.5 \pm 0.005) \mathrm{mm}\) and length \((6 \pm 0.06) \mathrm{cm}\). The maximum percentage error in the measurement of its density is

In Young's double slit experiment, the distance between the slits and the screen is \(1.2 \mathrm{~m}\) and the distance between the two slits is \(2.4 \mathrm{~mm}\). If a thin transparent mica sheet of thickness \(1 \mu \mathrm{m}\) and R...

Three polaroid sheets \(P_1, P_2\) and \(P_3\) are kept parallel to each other such that the angle between pass axes of \(P_1\) and \(P_2\) is \(45^{\circ}\) and that between \(P_2\) and \(P_3\) is \(45^{\circ}\). If unpolarised beam of lig...

Two poles are separated by a distance of \(3.14 \mathrm{~m}\). The resolving power of human eye is \(1 \mathrm{~min}\) of an arc. The maximum distance from which he can identify the two poles distinctly is

A train whistling at constant frequency \(n\) is moving towards a station at a constant speed \(v\). The train goes past a stationary observer on the station. The frequency \(n\) of the sound as heard by the observer is plotted as a functio...

A body is initially at rest. It undergoes one-dimensional motion with constant acceleration. The power delivered to it at time \(t\) is proportional to