Fusion reaction is initiated with the help of

A light with an energy flux of \(18 \mathrm{~W} \mathrm{~cm}^{-2}\) falls on a non-reflecting surface at normal incidence. If the surface has an area of \(20 \mathrm{~cm}^2\), the average force exerted on the surface during a 30 minute time span is ____ \(\left(c=3 \times 10^8 \mathrm{~ms}^{-1}\right)\).

At a given instant of time two particles are having the position vectors \(4 \hat{\mathbf{i}}+4 \hat{\mathbf{j}}+57 \hat{\mathbf{k}}\) metres and \(2 \hat{\mathbf{i}}+2 \hat{\mathbf{j}}+5 \hat{\mathbf{k}}\) respectively. If the velocity of the first particle be \(0.4 \hat{\mathbf{i}} \mathrm{ms}^{-1}\), the velocity of second particle in metre per second if they collide after \(10 \mathrm{sec}\) is

The waves having maximum wavelength among the following electromagnetic waves is

A block is lying at rest inside a bus. The maximum acceleration of the bus such that the block remain stationary (the static friction coefficient \(=02\), acceleration due to gravity \(=10 \mathrm{~ms}^{-2}\) )

A conductor moving in the magnetic field \(B\) and the induced current is \(I\). If the magnetic field is doubled the induced current will

Total emf produced in a thermocouple does not depend on

A coil having 500 square loops each of side 10 \(\mathrm{cm}\) is placed normal to a magnetic flux which increases at a rate of \(1 \mathrm{Ts}^{-1}\). The induced emf is

From the following data
\[
\begin{aligned}
& \mathrm{CH}_3 \mathrm{OH}(l)+\frac{3}{2} \mathrm{O}_2(g) \longrightarrow \mathrm{CO}_2(g)+2 \mathrm{H}_2 \mathrm{O}(l) \\
& \Delta_r H^{\circ}=-726 \mathrm{~kJ} \mathrm{~mol}^{-1} \\
& \mathrm{H}_2(g)+\frac{1}{2} \mathrm{O}_2(g) \longrightarrow \mathrm{H}_2 \mathrm{O}(l) \text {; } \\
& \Delta_r \mathrm{H}^{\circ}=-286 \mathrm{~kJ} \mathrm{~mol}^{-1} \\
& \mathrm{C}(\text { graphite })+\mathrm{O}_2(\mathrm{~g}) \longrightarrow \mathrm{CO}_2(\mathrm{~g}) \text {; } \\
& \Delta_r \mathrm{H}^{\circ}=-393 \mathrm{~kJ} \mathrm{~mol}^{-1} \\
&
\end{aligned}
\]
The standard enthalpy of formation of \(\mathrm{CH}_3 \mathrm{OH}(l)\) in \(\mathrm{kJ} \mathrm{mol}^{-1}\) is

The standard deviation of the numbers $22, 26, 28, 20, 24, 30$ is

An amplitude modulate wave is represented by \(10\left[1+0.6 \sin \left(40 \times 10^3 t\right)\right] \sin \left(4 \times 10^6 t\right)\) volt where \(t\) is in seconds. Then the ratio of the upper to the lower side band frequencies is

In \(\triangle \mathrm{ABC}\), if \(\sin ^2 \mathrm{~B}=\sin \mathrm{C}\) and \(3 \cos ^2 \mathrm{~B}=2 \cos ^2 \mathrm{C}\), then \(\triangle \mathrm{ABC}\) is

Assertion $\left(\mathrm{A}\right):$ If $\sqrt{4{\sin }^4\theta +{\sin }^{2}2\theta }+4{\cos }^2\left(\frac{\pi }{4}-\frac{\theta }{2}\right)=2,$ then $\theta$ lies in $3^{\mathrm{rd}}$ quadrant or $4^{\mathrm{th}}$ quadrant.
Reason $\left(\mathrm{R}\right): \sqrt{{\sin }^2\theta }=\sin \theta$