NTA JEE Main 11th April 2015 Online

Two long straight parallel wires, carrying (adjustable) currents $$I_1$$ and $$I_2$$, are kept at a distance $$d$$ apart. If the force $$F$$ between the two wires is taken as 'positive' when the wires repel each other and 'negative' when the wires attract each other, the graph showing the dependence of $$F$$, on the product $$I_1 I_2$$, would be:

The AC voltage across a resistance can be measured using a:

For the LCR circuit, shown here, the current is observed to lead the applied voltage. An additional capacitor $$C'$$, when joined with the capacitor C present in the circuit, makes the power factor of the circuit unity. The capacitor $$C'$$, must have been connected in:

For plane electromagnetic waves propagating in the $$+z$$-direction, which one of the following combinations gives the correct possible direction for $$\vec{E}$$ and $$\vec{B}$$ field respectively?

A thin convex lens of focal length $$f$$ is put on a plane mirror as shown in the figure. When an object is kept at a distance $$a$$ from the lens-mirror combination, its image is formed at a distance $$\dfrac{a}{3}$$ in front of the combination. The value of $$a$$ is:

In a Young's double slit experiment with light of wavelength $$\lambda$$, the separation of slits is $$d$$ and distance of screen is $$D$$ such that $$D \gg d \gg \lambda$$. If the Fringe width is $$\beta$$, the distance from point of maximum intensity to the point where intensity falls to half of the maximum intensity on either side is:

Unpolarized light of intensity $$I_0$$ is incident on surface of a block of glass at Brewster's angle. In that case, which one of the following statements is true?

The de-Broglie wavelength associated with the electron in the $$n = 4$$ level is:

Let $$N_\beta$$ be the number of $$\beta$$ particle emitted by 1 gram of Na$$^{24}$$ radioactive nuclei having a half life of 15 h. In 7.5 h, the number $$N_\beta$$ is close to $$[N_A = 6.023 \times 10^{23}$$ mole$$^{-1}]$$

The value of the resistor, $$R_S$$, needed in the DC voltage regulator circuit shown here, equals: