In a common emitter transistor amplifier, the output voltage and input voltage have a phase difference of

A solenoid having 400 turns per metre has a core of a material with relative permeability 400. When a current of 0.5 A is passed through it, the magnetization of the core material in \(\mathrm{Am}^{-1}\) is nearly

The variation of stopping potential for metals A, B, \(C\) and D with frequency of incident radiation is as shown in the figure. For which metal, stopping potential is higher for lower values of threshold frequency \(\left(v_{o}\right)\) ?
[The frequency of incident radiation, ' \(v^{\prime}\) is same.]

A system consists of three particles each of mass ' \(\mathrm{m}_1\) ' placed at the corners of an equilateral triangle of side ' \(\frac{\mathrm{L}}{3}\), A particle of mass ' \(\mathrm{m}_2\) ' is placed at the mid point of any one side of the triangle. Due to the system of particles, the force acting on \(\mathrm{m}_2\) is

The wavelength of sound in any gas depends upon

A disc has mass \(M\) and radius \(R\). How much tangential force should be applied to the rim of the disc, so as to rotate with angular velocity ' \(\omega\) ' in time \(t\) ?

At any time ' \(t\) ', the co-ordinates of moving particle are \(x=a t^2\) and \(\mathrm{y}=\mathrm{bt}^2\). The speed of the particle is

The incenter and centroid of the triangle, whose vertices are \(A \equiv(0,3,0), B \equiv(0,0,4)\), and \(C \equiv(0,3,4)\), are respectively given by

Let \(\overline{\mathrm{a}}, \overline{\mathrm{b}}, \overline{\mathrm{c}}\) be three non-coplanar vectors and \(\overline{\mathrm{p}}, \overline{\mathrm{q}}, \overline{\mathrm{r}}\) defined by the relations
\(\overline{\mathrm{p}}=\frac{\overline{\mathrm{b}} \times \overline{\mathrm{c}}}{[\overline{\mathrm{a}} \overline{\mathrm{~b}} \overline{\mathrm{c}}]}, \overline{\mathrm{q}}=\frac{\overline{\mathrm{c}} \times \overline{\mathrm{a}}}{[\overline{\mathrm{a}} \overline{\mathrm{~b}} \overline{\mathrm{c}}]}, \overline{\mathrm{r}}=\frac{\overline{\mathrm{a}} \times \overline{\mathrm{b}}}{[\overline{\mathrm{a}} \overline{\mathrm{~b}} \overline{\mathrm{c}}]}\)
then the value of the expression \((\bar{a}+\bar{b}) \cdot \bar{p}+(\bar{b}+\bar{c}) \cdot \bar{q}+(\bar{c}+\bar{a}) \cdot \bar{r}\) is equal to

The Maximum value of \(\left(\frac{1}{x}\right)^x\) is

A certain mass of a gas occupies a volume of \(2 \mathrm{dm}^{3}\) at STP. At what temperature the volume of gas becomes double, keeping the pressure constant?

A coil of ' \(n\) ' turns and resistance \(R \Omega\) is connected in series with a resistance \(\frac{R}{2}\). The combination is moved for time 't' second through magnetic flux \(\Phi_1\) to \(\Phi_2\). The induced current in the circuit is

All of the following are the ill effects of particulate pollutants on human health EXCEPT __________