Download App

STD 12 - 5. Magnetism and matter — NEET STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceNEETSTD 12 - 5. Magnetism and matter4 Marks
Question
Force between two identical bar magnets whose centres are $r $ metre apart is $ 4.8\, N$ , when their axes are in the same line. If separation is increased to $2r,$ the force between them is reduced to.....$N$
✓

Answer

(d)In magnetic dipole, force $ \propto \frac{1}{{{r^4}}}$
Hence new force $ = \frac{{4.8}}{{{2^4}}} = \frac{{4.8}}{{16}} = 0.3\;N$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

NEET STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

A monkey of mass $20\,kg$ is holding a vertical rope. The rope will not break when a mass of $25\, kg$ is suspended from it but will break if the mass exceeds $25 \,kg$. What is the maximum acceleration with which the monkey can climb up along the rope ............ $m/{s^2}$ $(g = 10\,m/{s^2})$
→
Polar molecules are the molecules:
→
A stretched wire of length $110 cm$ is divided into three segments whose frequencies are in ratio $1 : 2 : 3$. Their lengths must be
→
$A$ ring of resistance $10\Omega$ , radius $10cm$ and $100$ turns is rotated at $a$ rate $100$ revolutions per second about a fixed axis which is perpendicular to a uniform magnetic field of induction $10mT$. The amplitude of the current in the loop will be nearly.....$A$ (Take : $\pi^2 = 10$)
→
The time period of a simple pendulum of length $L$ as measured in an elevator descending with acceleration $\frac{g}{3}$ is
→
$y = a\cos (kx + \omega t)$ superimposes on another wave giving a stationary wave having node at $x = 0.$ What is the equation of the other wave
→
For an ideal gas the instantaneous change in pressure $'{p} '$ with volume $'v'$ is given by the equation $\frac{{dp}}{{dv}}=-{ap} .$ If ${p}={p}_{0}$ at ${v}=0$ is the given boundary condition, then the maximum temperature one mole of gas can attain is :

(Here ${R}$ is the gas constant)

→
In a $YDSE$ experiment if $a$ slab whose refractive index can be varied is placed in front of one of the slits then the variation of resultant intensity at mid-point of screen with $‘\mu ’$ will be best represented by $(\mu \geq 1)$.[Assume slits of equal width and there is no absorption by slab]
→
One mole of an ideal gas $(\gamma = 1.4)$ is adiabatically compressed so that its temperature rises from $27\,^oC$ to $35\,^oC$ . The change in the internal energy of the gas is  .... $J$. (given $R = 8.3\,J/mole-K$ )
→
Which of the following forces cannot be a resultant of $5\, N$ and $7\, N$ force...........$N$
→