Vectors \(a \hat{i}+b \hat{j}+\hat{k}\) and \(2 \hat{i}-3 \hat{j}+4 \hat{k}\) are perpendicular to each other when \(3 a+2 b=7\), the ratio of a to \(b\) is \(\frac{x}{2}\). The value of \(x\) is \(..............\)

A body of mass \(200\,g\) is tied to a spring of spring constant \(12.5\,N / m\), while the other end of spring is fixed at point \(O\). If the body moves about \(O\) in a circular path on a smooth horizontal surface with constant angular speed \(5\,rad / s\), then the ratio of extension in the spring to its natural length will be :

An upright object is placed at a distance of \(40\, cm\) in front of a convergent lens of focal length \(20\, cm\). A convergent mirror of focal length \(10\, cm\) is placed at a distance of \(60\, cm\) on the other side of the lens. The position and size of the final image will be

A system of three charges are placed as shown in the figure. If  \(D > > d,\) the potential energy of the system is best given \(b\)

In the following circuit, the magnitude of current \(I _{ l }\), is \(............A\).

The region between \(y = 0\) and \(y = d\) contains a magnetic field \(\vec B = B\hat z\) A particle of mass \(m\) and charge \(q\) enters the region with a velocity \(\vec v = v\hat i\). If \(d = \frac{{mv}}{{2qB}}\) , the acceleration of the charged particle at the point of its emergence at the other side is

Hydrogen ion and singly ionized helium atom are accelerated, from rest, through the same potential difference. The ratio of final speeds of hydrogen and helium ions is close to......

If \(x\) and \(y\) coordinates of a projectile as a function of time \((t)\) are given as \(24t\) and \(43.6t-4.9t^2\), respectively, then the angle (in degrees) made by the projectile with horizontal when \(t=2\) s is ______.

In the given circuit diagram when the current reaches steady state in the circuit, the charge on the capacitor of capacitance \(C\) will be