KCET 2020

The power factor of \(R-L\) circuit is \(\frac{1}{\sqrt{3}}\). If the inductive reactance is \(2 \Omega\). The value of resistance is

A \(220 \mathrm{~V}\) AC supply is connected between points \(A\) and \(B\) as shown in figure, what will be the potential difference \(V\) across the capacitor?

In the given circuit, the resonant frequency is

In the given circuit the peak voltage across \(C, L\) and \(R\) are \(30 \mathrm{~V}, 110 \mathrm{~V}\) and \(60 \mathrm{~V}\), respectively. The rms value of the applied voltage is

The period of revolution of an electron revolving in nth orbit of \(\mathrm{H}\)-atom is proportional to

Two protons are kept at a separation of \(10 \mathrm{~nm}\). Let \(F_n\) and \(F_e\) the nuclear force and the electromagnetic force between them

Angular momentum of an electron in hydrogen atom is \(\frac{3 h}{2 \pi}\) (\(h\) is the Planck's constant). The KE of the electron is

During a \(\beta^{-}\)-decay

A radio-active elements has half-life of 15 years. What is the fraction that will decay in 30 years?

A beam of fast moving alpha particles were directed towards a thin film of gold. The parts \(A, B\) and \(C\) of the transmitted and reflected beams corresponding to the incident parts \(A, B\) and \(C\) of the beam are shown in the adjoini...

The difference between equivalent capacitances of two identical capacitors connected in parallel to that in series is \(6 \mu \mathrm{F}\). The value of capacitance of each capacitor is

One end of a string of length \(l\) is connected to a particle of mass \(m\) and the other to a small peg on a smooth horizontal table. If the particle moves in a circle with speed \(v\), the net force on the particle (directed towards the ...

The colour code for a carbon resistor of resistance \(0.2 \mathrm{k} \Omega \pm 10 \%\) is

A metal rod of length \(10 \mathrm{~cm}\) and a rectangular cross-section of \(1 \mathrm{~cm} \times \frac{1}{2} \mathrm{~cm}\) is connected to a battery across opposite faces. The resistance will be

A car has a fresh storage battery of emf \(12 \mathrm{~V}\) and internal resistance \(2 \times 10^{-2} \Omega\). If the starter motor draws a current of \(80 \mathrm{~A}\). Then, the terminal voltage when the starter is On is

A potentiometer has a uniform wire of length \(5 \mathrm{~m}\). A battery of emf \(10 \mathrm{~V}\) and negligible internal resistance is connected between its ends. A secondary cell connected to the circuit gives balancing length at $$200 ...

Each resistance in the given cubical network has resistance of \(1 \Omega\) and equivalent resistance between \(A\) and \(B\) is

\(I-V\) characteristic of a copper wire of length \(L\) and area of cross-section \(A\) is shown in figure. The slope of the curve becomes

The de-Broglie wavelength associated with electron of hydrogen atom in this ground state is

A hot filament liberates an electron with zero initial velocity. The anode potential is \(1200 \mathrm{~V}\). The speed of the electron when it strikes the anode is

The following graph represents the variation of photocurrent with anode potential for a metal surface. Here \(I_1, I_2\) and \(I_3\) represents intensities and \(\gamma_1, \gamma_2, \gamma_3\) represent frequency for curves \(1,2\) and $$3$...

Young's modulus of a perfect rigid body is

The current in a coil of inductance \(0.2 \mathrm{H}\) changes from \(5 \mathrm{~A}\) to \(2 \mathrm{~A}\) in \(0.5 \mathrm{~s}\). The magnitude of the average induced emf in the coil is

A rod of length \(2 \mathrm{~m}\) slides with a speed of \(5 \mathrm{~ms}^{-1}\) on a rectangular conducting frame as shown in figure. There exists a uniform magnetic filed of \(0.04 \mathrm{~T}\) perpendicular to the plane of the figure. I...

A light beam of intensity \(20 \mathrm{~W} / \mathrm{cm}^2\) is incident normally on a perfectly reflecting surface of sides \(25 \mathrm{~cm} \times 15 \mathrm{~cm}\). The momentum imparted to the surface by the light per second is

An infinitely long thin straight wire has uniform charge density of \(\frac{1}{4} \times 10^{-2} \mathrm{~cm}^{-1}\). What is the magnitude of electric field at a distance \(20 \mathrm{~cm}\) from the axis of the wire?

When a soap bubble is charged?

A dipole moment \(p\) and moment of inertia \(I\) is placed in a uniform electric field \(\mathbf{E}\). If it is displaced slightly from its stable equilibrium position, the period of oscillation of dipole is

A point charge \(q\) is placed at the corner of a cube of side \(a\) as shown in the figure. What is the electric flux through the face \(A B C D\) ?

Figure shows three points \(A, B\) and \(C\) in a region of uniform electric field \(\mathbf{E}\). The line \(A B\) is perpendicular and \(B C\) is parallel to the field lines. Then, which of the following holds good ? (\(V_A, V_B\) and $$V...

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