The angular acceleration of a body, moving along the circumference of a circle, is :

A parallel beam of light of wavelength \(\lambda\) is incident normally on a single slit of width \(d\). Diffraction bands are obtained on a screen placed at a distance \(D\) from the slit. The second dark band from the central bright band will be at a distance given by

Two blocks \(A\) and \(B\) of masses \(3\,m\) and \(m\) respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of \(A\) and \(B\) immediately after the string is cut, are respectively

A bob is whirled in a horizontal plane by means of a string with an initial speed of \(\omega \mathrm{rpm}\). The tension in the string is \(T\). If speed becomes \(2 \omega\) while keeping the same radius, the tension in the string becomes:

Given below are two statements: one is labelled as Assertion \(A\) and the other is labelled as Reason \(R\). Assertion \(A\): The potential ( \(V\) ) at any axial point, at \(2 \mathrm{~m}\) distance ( \(r\) ) from the centre of the dipole of dipole moment vector \(\vec{P}\) of magnitude, \(4 \times 10^{-6} \mathrm{C} \mathrm{m}\), is \(\pm 9 \times 10^3 \mathrm{~V}\). (Take \(\frac{1}{4 \pi \epsilon_0}=9 \times 10^9 \mathrm{Sl}\) units) Reason \(R\): \(V= \pm \frac{2 P}{4 \pi \epsilon_0 r^2}\), where \(r\) is the distance of any axial point, situated at \(2 \mathrm{~m}\) from the centre of the dipole. In the light of the above statements, choose the correct answer from the options given below:

A photon and an electron (mass \(m\) ) have the same energy \(E\). The ratio ( \(\lambda_{\text {photon }} / \lambda_{\text {electron }}\) ) of their de Broglie wavelengths is: ( c is the speed of light)

A solid cylinder of mass \(2\; kg\) and radius \(4 \;\mathrm{cm}\) is rotating about its axis at the rate of \(3\; \mathrm{rpm}\). The torque required to stop after \(2 \pi\) revolutions is

Secondary xylem and phloem in dicot stem are produced by

Which of the following is the most abundant protein in the animals?

The phenomenon of pleiotropism refers to

A room heater is rated 400 W, 220 V. If the supply voltage drops to 200 V, what will be the power consumed (approximately) ?

What is the function of silks in the corn cob?

In a Young's double slit experiment, a student observes \(8\) fringes in a certain segment of screen when a monochromatic light of \(600\,nm\) wavelength is used. If the wavelength of light is changed to \(400\,nm\), then the number of fringes he would observe in the same region of the screen is: