NTA JEE Main 9th April 2013 Online

Two coils, X and Y, are kept in close vicinity of each other. When a varying current, $$I(t)$$, flows through coil X, the induced emf $$(V(t))$$ in coil Y, varies in the manner shown here. The variation of $$I(t)$$, with time, can then be represented by the graph labelled as graph :

(A)

(B)

(c)

(D)

In the circuit shown here, the voltage across E and C are respectively 300 V and 400 V. The voltage E of the ac source is :

Photons of an electromagnetic radiation has an energy 11 keV each. To which region of electromagnetic spectrum does it belong?

Light is incident from a medium into air at two possible angles of incidence (A) 20° and (B) 40°. In the medium light travels 3.0 cm in 0.2 ns. The ray will :

A ray of light of intensity I is incident on a parallel glass slab at point A as shown in the diagram. It undergoes partial reflection and refraction. At each reflection, 25% of incident energy is reflected. The rays AB and A'B' undergo interference. The ratio of $$I_{max}$$ and $$I_{min}$$ is :

A person lives in a high-rise building on the bank of a river 50 m wide. Across the river is a well lit tower of height 40 m. When the person, who is at a height of 10 m, looks through a polarizer at an appropriate angle at light of the tower reflecting from the river surface, he notes that intensity of light coming from distance X from his building is the least and this corresponds to the light coming from light bulbs at height 'Y' on the tower. The values of X and Y are respectively close to (refractive index of water $$\sim \frac{4}{3}$$)

In the Bohr model an electron moves in a circular orbit around the proton. Considering the orbiting electron to be a circular current loop, the magnetic moment of the hydrogen atom, when the electron is in $$n^{th}$$ excited state, is :

When Uranium is bombarded with neutrons, it undergoes fission. The fission reaction can be written as :
$$_{92}U^{235} + {}_0n^1 \rightarrow {}_{56}Ba^{141} + {}_{36}Kr^{92} + 3x + Q$$(energy) where three particles named x are produced and energy Q is released. What is the name of the particle x?

Consider two npn transistors as shown in figure. If 0 Volts corresponds to false and 5 Volts correspond to true then the output at C corresponds to :

If a carrier wave $$c(t) = A\sin\omega_c t$$ is amplitude modulated by a modulator signal $$m(t) = A\sin\omega_m t$$ then the equation of modulated signal $$[C_m(t)]$$ and its modulation index are respectively