Two parallel long current carrying wire separated by a distance \(2 \mathrm{r}\) are shown in the figure. The ratio of magnetic field at \(\mathrm{A}\) to the magnetic field produced at \(C\) is \(\frac{x}{7}\). The value of \(x\) is _______.

In the figure, given that \(V_{BB}\) supply can vary from \(0\) to \(5.0 \,V,\,\,V_{CC} = 5\,V,\) \(\beta _{dc} = 200,\,\,R_B = 100,\,k\Omega ,\) \(R_C = 1\,k\Omega  \) an \(V_{BE} = 1.0\,V,\) The minimum base current and the input voltage at which the transistor will go to saturation, will be respectively

Two wires of same length and thickness having specific resistances \(6\, \Omega \,cm\) and \(3 \,\Omega\, cm\) respectively are connected in parallel. The effective resistivity is \(\rho\, \Omega \,cm\). The value of \(\rho\) to the nearest integer, is ..... .

A \(dc\) source of \(emf \,E_1 = 100\,V\) and internal resistance \(r = 0.5\,\Omega ,\) a storage battery of emf \(E_2 = 90\,V\) and an external resistance \(R\) are connected as shown in figure. For what value of \(R\) no current will pass through the battery ? ................ \(\Omega\)

Two bodies A and B of equal mass are suspended from two massless springs of spring constant \(k_1\) and \(k_2\), respectively. If the bodies oscillate vertically such that their amplitudes are equal, the ratio of the maximum velocity of \(A\) to the maximum velocity of \(B\) is _______.

For a constant collector-emitter voltage of \(8\,V\), the collector current of a transistor reached to the value of \(6\,mA\) from \(4\,mA\), whereas base current changed from \(20\,\mu A\) to \(25\,\mu\,A\) value. If transistor is in active state, small signal current gain (current amplification factor) will be.

A large number \((n)\) of identical beads, each of mass \(m\) and radius \(r\) are strung on a thin smooth rigid horizontal rod of length \(L\, (L >> r)\) and are at rest at random positions. The rod is mounted between two rigid supports (see figure) . If one of the beads is now given a speed \(v\), the average force experienced by each support after a long time is (assume all collisions are elastic)

This questions has Statement \(I\) and Statement \(II\) Of the four choices given after the Statements, choose the one that best describes into two Statements.
Statement\(-I\) : Higher the range, greater is the resistance of ameter.
Statement\(-II\) : To increase the range of ammeter, additional shunt needs to be used across it.

In an experiment a sphere of aluminium of mass \(0.20\, kg\) is heated upto \(150\,^oC\). Immediately, it is put into water of volume \(150\, cc\) at \(27\,^oC\) kept in a calorimeter of water equivalent to \(0.025\, kg\). Final temperature of the system is \(40\,^oC\). The specific heat of aluminium is ............ \(J/kg\,-\,^oC\) (take \(4.2\, Joule= 1\, calorie\))

The electric field component of a monochromatic radiation is given by \(\vec E = 2{E_0}\,\hat i\,\cos\, kz\,\cos\, \omega t\) Its magnetic field \(\vec B\) is then given by

In an experiment of determine the Young's modulus of wire of a length exactly \(1\; m\), the extension in the length of the wire is measured as \(0.4\,mm\) with an uncertainty of \(\pm 0.02\,mm\) when a load of \(1\,kg\) is applied. The diameter of the wire is measured as \(0.4\,mm\) with an uncertainty of \(\pm 0.01\,mm\). The error in the measurement of Young's modulus \((\Delta Y)\) is found to be \(x \times 10^{10}\,Nm ^{-2}\). The value of \(x\) is \(\left[\right.\) Take \(\left.g =10\,m / s ^{2}\right]\)

A uniform string oflength \(20\ m\) is suspended from a rigid support. A short wave pulse is introduced at its lowest end. It starts moving up the string. The time taken to reach the supports is (take \(g= 10 \) \(ms^{-2}\) )