For the circuit shown, with \({R_1} = 1.0\,\Omega \), \({R_2} = 2.0\,\Omega \), \({E_1} = 2\,V\) and \({E_2} = {E_3} = 4\,V\), the potential difference between the points \(‘a’\) and \(‘b’\) is approximately (in \(V\))

A charged particle going around in a circle can be considered to be a current loop. A particle of mass \(m\) carrying charge \(q\) is moving in a plane with speed \(v\) under the influence of magnetic field \(\overrightarrow{ B }\). The magnetic moment of this moving particle

A hot body, obeying Newton's law of cooling is cooling down from its peak value \(80\,^oC\) to an ambient temperature of \(30\,^oC\) . It takes \(5\, minutes\) in cooling down from \(80\,^oC\) to \(40\,^oC\).  ........  \(\min.\) will it take to cool down from \(62\,^oC\) to \(32\,^oC\) ? (Given \(ln\, 2\, = 0.693, ln\, 5\, = 1.609\))

The time period of revolution of electron in its ground state orbit in a hydrogen atom is \(1.6 \times 10^{-16} \;\mathrm{s}\). The frequency of revolution of the electron in its first excited state (in \(s^{-1}\) ) is:

A square shaped hole of side \(l=\frac{a}{2}\) is carved out at a distance \(d =\frac{ a }{2}\) from the centre \('O'\) of a uniform circular disk of radius \(a\). If the distance of the centre of mass of the remaining portion from \(O\) is \(-\frac{a}{X},\) value of \(X\) (to the nearest integer) is.......

A potentiometer \(PQ\) is set up to compare two resistances as shown in the figure. The ameter \(A\) in the circuit reads \(1.0\, A\) when two way key \(K_3\) is open. The balance point is at a length \(l_1\, cm\) from \(P\) when two way key \(K_3\) is plugged in between \(2\) and \(1\) , while the balance point is at a length \(l_2\, cm\) from \(P\) when key \(K_3\) is plugged in between \(3\) and \(1\) . The ratio of two resistances \(\frac{{{R_1}}}{{{R_2}}}\) is found to be

In a linear simple harmonic motion \((SHM)\) \((A)\) Restoring force is directly proportional to the displacement. \((B)\) The acceleration and displacement are opposite in direction. \((C)\) The velocity is maximum at mean position. \((D)\) The acceleration is minimum at extreme points. Choose the correct answer from the options given below :

A transformer consisting of \(300\) turns in the primary and \(150\) turns in the secondary gives output power of \(2.2\, kW\). If the current in the secondary coils is \(10\, A\), then the input voltage and current in the primary coil are

If the radius of the largest circle with centre \((2,0)\) inscribed in the ellipse \(x^2+4 y^2=36\) is \(r\), then \(12 r^2\) is equal to

If \(a > 0\) and \(z = \frac{{{{\left( {1 + i} \right)}^2}}}{{a - i}}\), has magnitude \(\sqrt {\frac{2}{5}} \), then \(\bar z\) is equal to:

The least count of the main scale of a vernier callipers is \(1\, mm\). Its vernier scale is divided into \(10\) divisions and coincide with \(9\) divisions of the main scale. When jaws are touching each other, the \(7\) th division of vernier scale coincides with a division of main scale and the zero of vernier scale is lying right side of the zero of main scale. When this vernier is used to measure length of a cylinder the zero of the vernier scale between \(3.1\, cm\) and \(3.2\, cm\) and \(4^{th}\) \(VSD\) coincides with a main scale division.The length of the cylinder is \(.....cm\) (\(VSD\) is vernier scale division)

The number of integral values of \(m\) for which the quadratic expression, \((1 + 2m)x^2 -2(1+ 3m)x + 4(1 + m),\) \(x\in R,\) is always positive, is

When one light ray is reflected from a plane mirror with \(30^{\circ}\) angle of reflection, the angle of deviation of the ray after reflection is \(.....^{\circ}\)