NTA JEE Main 25th April 2013 Online

In a transverse wave the distance between a crest and neighbouring trough at the same instant is 4.0 cm and the distance between a crest and trough at the same place is 1.0 cm. The next crest appears at the same place after a time interval of 0.4 s. The maximum speed of the vibrating particles in the medium is:

This question has Statement-1 and Statement-2. Of the four choices given after the Statements, choose the one that best describes the two Statements.
Statement 1: No work is required to be done to move a test charge between any two points on an equipotential surface.
Statement 2: Electric lines of force at the equipotential surfaces are mutually perpendicular to each other.

The surface charge density of a thin charged disc of radius R is $$\sigma$$. The value of the electric field at the centre of the disc is $$\frac{\sigma}{2\epsilon_0}$$. With respect to the field at the centre, the electric field along the axis at a distance R from the centre of the disc:

The gravitational field in a region is given by: $$\vec{E} = (5N/kg)\hat{i} + (12N/kg)\hat{j}$$. If the potential at the origin is taken to be zero, then the ratio of the potential at the points (12 m, 0) and (0, 5 m) is :

A parallel plate capacitor having a separation between the plates d, plate area A and material with dielectric constant K has capacitance $$C_0$$. Now one-third of the material is replaced by another material with dielectric constant 2K, so that effectively there are two capacitors one with area $$\frac{1}{3}$$ A, dielectric constant 2K and another with area $$\frac{2}{3}$$ A and dielectric constant K. If the capacitance of this new capacitor is C then $$\frac{C}{C_0}$$ is

Six equal resistances are connected between points P, Q and R as shown in figure. Then net resistance will be maximum between :

The earth's magnetic field lines resemble that of a dipole at the centre of the earth. If the magnetic moment of this dipole is close to $$8 \times 10^{22}$$ Am$$^2$$, the value of earth's magnetic field near the equator is close to (radius of the earth = $$6.4 \times 10^6$$ m)

One of the two small circular coils, (none of them having any self-inductance) is suspended with a V-shaped copper wire, with plane horizontal. The other coil is placed just below the first one with plane horizontal. Both the coils are connected in series with a dc supply. The coils are found to attract each other with a force. Which one of the following statements is incorrect?

A metal sample carrying a current along X-axis with density $$J_x$$ is subjected to a magnetic field $$B_z$$ (along z-axis). The electric field $$E_y$$ developed along Y-axis is directly proportional to $$J_x$$ as well as $$B_z$$. The constant of proportionality has SI unit.

When resonance is produced in a series LCR circuit, then which of the following is not correct?