List of top Questions asked in COMEDK UGET

The resistance of a wire is \(5\,ohm\) at \(25^\circ C\) and \(7\,ohm\) at \(100^\circ C\). The resistance of the wire at \(0^\circ C\) is

Two identical conductors of lengths \(l\) and \(3l\) respectively are maintained at the same temperature. They are given potential differences in the ratio \(1:3\). The ratio of their drift velocities is

If voltage across a bulb rated \(220\,V, 50\,W\) drops by \(5\%\) of its rated value, the percentage of the rated value by which the power would decrease is

Two identical conducting balls having positive charges \(q_1\) and \(q_2\) are separated by a distance \(r\). If they are made to touch each other and then separated to the same distance, the force between them will be

A bomb of mass \(20\,kg\) at rest explodes into two pieces of masses \(12\,kg\) and \(8\,kg\). If the velocity of \(8\,kg\) mass is \(6\,ms^{-1}\), then the kinetic energy of the other mass is:

A vertical spring of spring constant \(24Nm^{-1}\) is fixed on a table. A ball of mass \(0.5\,kg\) at a height \(2\,m\) above the free upper end of the spring falls vertically on the spring so that the spring is compressed by a distance of \(50\,cm\). The net work done in the process is:

Two simple harmonic motions are represented by equations \(y_1 = 0.5 \sin [200\pi t + \frac{\pi}{3}]\) and \(y_2 = 0.5 \cos \pi t\). The phase difference of the velocity of particle 1 with respect to the velocity of particle 2 is:

For the charge configuration shown here, which of the following is not true?

A convex lens forms a real image of an object with magnification \(m_1\). The lens is moved towards the object to obtain another real image of magnification \(m_2\). The image distance is increased by \(x\). The focal length of the lens is

A charged particle is released from rest in a region of space in which steady and uniform electric and magnetic fields are parallel to each other. The particle will move in a

If \(E\) is the amplitude of the electric field of the waves starting from the slits in a double slit experiment and \(\theta\) is the phase difference between the waves reaching a point on the screen, the ratio of the amplitude of the resultant electric field at that point on the screen to the amplitude at one of the slits is

A Si and a Ge diode has identical physical dimensions. The band gap in Si is larger than that in Ge. On applying identical reverse bias across these diodes,

Two coherent waves of intensities \(I_1\) and \(I_2\) pass through a region at the same time in the same direction. The sum of maximum to minimum intensities is

A wooden block floats with \(\frac{3}{5}\) of its volume submerged in a tank of water. If a denser liquid is poured into the tank, the wooden block floats with half its volume in the liquid and the remaining half in water. The relative density of the liquid is:

Emission of electrons from a metal plate illuminated with monochromatic electromagnetic radiation will always take place provided

A particle starts from rest and moves along the \(x\)-axis with a velocity that varies as \(v = \sqrt{100 + 4x}\,\text{ms}^{-1}\). The acceleration of the particle is:

A bulb of resistance \(280\,\Omega\) is supplied with a voltage \(V = 400\sin \pi t\). The peak current is

Two very long, straight, parallel wires carry steady currents \(I\) and \(2I\) respectively. The distance between the wires is \(d\). At a certain instant of time, a point charge \(q\) is at a point equidistant from the two wires, in the plane of the wires. Its instantaneous velocity \(v\) is perpendicular to this plane. The magnitude of the force due to the magnetic field acting on the charge at this instant is

One surface of a lens is convex and the other is concave. If the radii of curvatures are \(R\) and \(r\) respectively, the lens will be convex if

The magnetic flux \( \phi \) through a stationary loop of wire having a resistance \( R \) varies with time as \( \phi = 4t^2 + 3t \). The average emf and total charge flowing in the loop in the time interval \( t = 0 \) to \( t = \tau \) respectively are

If \(R\) and \(L\) denote resistance and inductance of a material, then the dimension of \(LR\) will be:

A stone is dropped from a height \(h\). It hits the ground with a certain momentum \(p\). If the same stone is dropped from a different height \(h'\) such that percentage change in momentum is \(41.4\%\), then the height from which the stone is dropped is \(h' = xh\), where \(x\) is:

Two capacitors \(C_1\) and \(C_2\) are charged to \(100\,V\) and \(120\,V\) respectively. It is found that upon connecting them together in parallel, the potential on each one of them is zero. Therefore

A galvanometer of resistance \(50\Omega\) is connected to a battery of \(4\,V\) along with a resistance of \(3950\Omega\) in series. A full-scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 10 divisions, the resistance in series should be equal to:

Point charges \(-3Q, -q, 2q\) and \(2Q\) are placed, one at each corner of a square. The relation between \(Q\) and \(q\) for which the potential at the centre of the square is zero is