NTA JEE Main 4th September 2020 Shift 2

The driver of bus approaching a big wall notices that the frequency of his bus's horn changes from 420 Hz to 490 Hz when he hears it after it gets reflected from the wall. Find the speed of the bus if speed of the sound is 330 ms$$^{-1}$$:

A capacitor C is fully charged with voltage $$V_0$$. After disconnecting the voltage source, it is connected in parallel with another uncharged capacitor of capacitance $$\frac{C}{2}$$. The energy loss in the process after the charge is distributed between the two capacitors is:

The value of current $$i_1$$ flowing from A to C in the circuit diagram is:

A paramagnetic sample shows a net magnetisation of 6 A/m when it is placed in an external magnetic field of 0.4 T at a temperature of 4 K. When the sample is placed in an external magnetic field of 0.3 T at a temperature of 24 K, then the magnetisation will be:

A circular coil has moment of inertia 0.8 kg m$$^2$$ around any diameter and is carrying current to produce a magnetic moment of 20 Am$$^2$$. The coil is kept initially in a vertical position and it can rotate freely around a horizontal diameter. When a uniform magnetic field of 4 T is applied along the vertical, it starts rotating around its horizontal diameter. The angular speed the coil acquires after rotating by 60° will be:

A series $$L - R$$ circuit is connected to a battery of emf $$V$$. If the circuit is switched on at $$t = 0$$, then the time at which the energy stored in the inductor reaches $$\left(\frac{1}{n}\right)$$ times of its maximum value, is:

The electric field of a plane electromagnetic wave is given by $$\vec{E} = E_0(\hat{x} + \hat{y})\sin(kz - \omega t)$$. Its magnetic field will be given by

In a photoelectric effect experiment, the graph of stopping potential $$V$$ versus reciprocal of wavelength obtained is shown in the figure. As the intensity of incident radiation is increased:

Find the Binding energy per nucleon for $$^{120}_{50}Sn$$. Mass of proton $$m_p = 1.00783$$ U, mass of neutron $$m_n = 1.00867$$ U and mass of tin nucleus $$m_{sn} = 119.902199$$ U. (take 1U = 931 MeV)

Identify the operation performed by the circuit given below: