A moving coil galvanometer has a coil of effective area \( A \), number of turns \( N \). The magnetic field \( B \) is radial. If current \( I \) is passed through the coil, the torque acting on the coil is:

The frequency of revolution of an electron revolving in a circular path in a magnetic field of \( 7.8 \times 10^{-4} \, \text{T} \) will be (Take \( e = -1.6 \times 10^{-19} \, \text{C} \), \( m_e = 9.1 \times 10^{-31} \, \text{kg} \), \( \pi = 22/7 \))

Two concentric coils \(X\) and \(Y\), each of radius \(2 \pi cm\), are placed at right angles to each other. If \(X\) and \(Y\) carry 4 A and 3 A currents, respectively, then the value of the magnetic field (in \(Wb m ^{-2}\) ) at the centre of the coils is (Take \(\mu_0=4 \pi \times 10^{-7} Wb A ^{-1} m^{-1}\) )

Two slits are kept 1 mm apart and the screen is placed 1.0 m away. What is the fringe separation when blue-green light of wavelength 500 nm is used ?

The core of a transformer is laminated to:

A cylindrical bar magnet is kept along the axis of circular coil. If the magnet is rotated about its axis, then :

Arrange the following substances in the increasing order of magnetic susceptibility.
(A) Paramagnetic substances
(B) Superconductors
(C) Diamagnetic substances
(D) Ferromagnetic substances
Choose the correct answer from the options given below :

Alcohol is a depressant, which means that even small amounts of alcohol slow down the actions of parts of the brain, so alcohol lengthens the time you take to respond to a stimulus.
Different people react differently to alcohol. In some people, it increase their feelings of aggression, and releases their inhibitions so that they are more likely to be violent or commit other crimes.
An alcoholic needs to drink quite large quantities of alcohol regularly. This causes many parts of the body to be damaged, because alcohol is poisonous to cells. Probably, there are many factors which decide whether or not a person becomes alcoholic. Over a long period of time, it can cause loss of memory and confusion. One way in which the damage is done is that alcohol in the body fluids draws water out of cells by osmosis.
Effect of alcohol on cells is -

\(^{70}Yb^{2+}\) and \(^{71}Lu^{3+}\) Lanthanoid ions are..........

For the given linear programming problem \(z=a x+b y, a, b>0\) subject to the constraint
\(2 x+y \leq 10, x+3 y \leq 15, x, y \geq 0\). If the corner points are \((0,0),(5,0),(3,4)\) and \((0,5)\) and \(z\) is maximum at both \((3,4)\) and \((0,5)\), then the relationship between \(a\) and \(b\) is

\(\vec{n}\) is a vector of magnitude \(2 \sqrt{3}\) such that it makes equal angles with coordinate axes. The vector equation of the plane passing through (1, -1, 2) and perpendicular to \(\vec{n}\) is:

Osmotic pressure measurements are less accurate and difficult to carry out. Therefore, this method is not useful for measuring molecular weights. But it is used to find out molecular weights of polymers eg. plastics, proteins and starch having many monomer units. Knowing the value of osmotic pressure of a given solution, molecular weight of the solute can be calculated using Van't Hoff equation.
An aqueous solution of salt contains 20 g of NaCl per liter. The pressure of solution at 35 \(^{\circ}\text{C}\) will be:

A proton of charge \(1.6 \times 10^{-19} C\) is moving with a velocity of \(5 \times 10^3 m / s\) in a magnetic field of 4 T. The work done by the magnetic field on the proton is :