A small cube of side \(1\) mm is placed at the centre of a circular loop of radius \(10\) cm carrying a current of \(2\) A. The magnetic energy stored inside the cube is \(\alpha \times 10^{-14}\) J. The value of \(\alpha\) is _______. (\(\mu_o = 4\pi \times 10^{-7}\) Tm/A, \(\pi = 3.14\))

A galvanometer has a resistance of \(50 \Omega\) and allows a maximum current of \(5 \mathrm{~mA}\) to pass. What is the necessary series resistance to connect to convert it to a voltmeter that can measure \(100 \mathrm{~V}\)?

First, a set of \({n}\) equal resistors of \(10\; \Omega\) each are connected in series to a battery of emf \(20\; {V}\) and internal resistance \(10\; \Omega .\) A current \(I\) is observed to flow. Then, the \(n\) resistors are connected in parallel to the same battery. It is observed that the current is increased \(20\) times, then the value of \(n\) is .... .

In a Young's double slit experiment, \(16\) fringes are observed in a certain segment of the screen when light of wavelength \(700 \,nm\) is used. If the wavelength of light is changed to \(400 \,nm\), the number of fringes observed in the same segment of the screen would be........

A body of mass \(m\) is taken from the surface of earth to a height equal to twice the radius of earth (\(R_e\)). The increase in potential energy will be _______.
(\(g\) is acceleration due to gravity at the surface of earth)

Let \(\sigma\) be the uniform surface charge density of two infinite thin plane sheets shown in figure. Then the electric fields in three different region \(E_{ I }, E_{ II }\) and \(E_{III}\) are

The specific heat of water \(=4200\, J\, kg ^{-1}\, K ^{-1}\) and the latent heat of ice \(=3.4 \times 10^{5}\, J\, kg ^{-1}.\) \(100\) grams of ice at \(0^{\circ} C\) is placed in \(200\, g\) of water at \(25^{\circ} C\). The amount of ice that will melt as the temperature of water reaches \(0^{\circ} C\) is close to (in \(grams\)) 

Let the eccentricity of an ellipse \(\frac{x^{2}}{a^{2}}+\frac{y^{2}}{b^{2}}=1, a>b\), be \(\frac{1}{4}\). If this ellipse passes through the point \(\left(-4 \sqrt{\frac{2}{5}}, 3\right)\), then \(a^{2}+b^{2}\) is equal to

The source that illuminates the double - slit in 'double - slit interference experiment' emits two distinct monochromatic waves of wavelength \(500\,nm\) and \(600\, nm\), each of them producing its own pattern on the screen. At the central point of the pattern when path difference is zero, maxima of both the patterns coincide and the resulting interference pattern is most distinct at the region of zero path difference. But as one moves out of this central region, the two fringe systems are gradually out of step such that maximum due to on wavelength coincides with the minimum due to the other and the combined fringe system becomes completely indistinct. This may happen when path difference in \(nm\) is

If \(\left[ {a \times b\;\;b \times c\;\;c \times a} \right] = \lambda \;{\left[ {a\;\;b\;\;c} \right]^2}\) then \(\lambda\) is equal to 

In a hydraulic lift, the surface area of the input piston is \(6 \mathrm{~cm}^2\) and that of the output piston is \(1500 \mathrm{~cm}^2\). If 100 N force is applied to the input piston to raise the output piston by 20 cm, then the work done is _______ kJ.

Let \(S\) be the set of all \(a \in N\) such that the area of the triangle formed by the tangent at the point \(P ( b , c ), b , c \in N\), on the parabola \(y ^2=2 ax\) and the lines \(x=b, y=0\) is \(16\) unit \(^2\), then \(\sum_{\text {aes }} a\) is equal to \(..........\).

Let the image of the point \(P (2,-1,3)\) in the plane \(x+2 y-z=0\) be \(Q\). Then the distance of the plane \(3 x+2 y+z+29=0\) from the point \(Q\) is \(.........\).