NTA JEE Main 27th July 2022 Shift 2

A. The drift velocity of electrons decreases with the increase in the temperature of conductor.
B. The drift velocity is inversely proportional to the area of cross-section of given conductor.
C. The drift velocity does not depend on the applied potential difference to the conductor.
D. The drift velocity of electron is inversely proportional to the length of the conductor.
E. The drift velocity increases with the increase in the temperature of conductor.
Choose the correct answer from the options given below:

A compass needle of oscillation magnetometer oscillates 20 times per minute at a place P of dip $$30^\circ$$. The number of oscillations per minute become 10 at another place Q of $$60^\circ$$ dip. The ratio of the total magnetic field at the two places $$(B_Q : B_P)$$ is:

A cyclotron is used to accelerate protons. If the operating magnetic field is 1.0 T and the radius of the cyclotron 'dees' is 60 cm, the kinetic energy of the accelerated protons in MeV will be: [use $$m_p = 1.6 \times 10^{-27}$$ kg, $$e = 1.6 \times 10^{-19}$$ C]

A series LCR circuit has $$L = 0.01$$ H, $$R = 10 \ \Omega$$ and $$C = 1 \ \mu F$$ and it is connected to ac voltage of amplitude $$(V_m)$$ 50 V. At frequency 60% lower than resonant frequency, the amplitude of current will be approximately

Identify the correct statements from the following descriptions of various properties of electromagnetic waves.
A. In a plane electromagnetic wave electric field and magnetic field must be perpendicular to each other and direction of propagation of wave should be along electric field or magnetic field.
B. The energy in electromagnetic wave is divided equally between electric and magnetic fields.
C. Both electric field and magnetic field are parallel to each other and perpendicular to the direction of propagation of wave.
D. The electric field, magnetic field and direction of propagation of wave must be perpendicular to each other.
E. The ratio of amplitude of magnetic field to the amplitude of electric field is equal to speed of light.
Choose the most appropriate answer from the options given below:

Two coherent sources of light interfere. The intensity ratio of two sources is $$1 : 4$$. For this interference pattern if the value of $$\frac{I_{max}+I_{min}}{I_{max}-I_{min}}$$ is equal to $$\frac{2\alpha+1}{\beta+3}$$, then $$\frac{\alpha}{\beta}$$ will be

With reference to the observations in photo-electric effect, identify the correct statements from below:
A. The square of maximum velocity of photoelectrons varies linearly with frequency of incident light.
B. The value of saturation current increases on moving the source of light away from the metal surface.
C. The maximum kinetic energy of photo-electrons decreases on decreasing the power of LED (light emitting diode) source of light.
D. The immediate emission of photo-electrons out of metal surface can not be explained by particle nature of light/electromagnetic waves.
E. Existence of threshold wavelength can not be explained by wave nature of light/electromagnetic waves.
Choose the correct answer from the options given below:

The activity of a radioactive material is $$6.4 \times 10^{-4}$$ curie. Its half life is 5 days. The activity will become $$5 \times 10^{-6}$$ curie after

For a constant collector-emitter voltage of 8 V, the collector current of a transistor reached to the value of 6 mA from 4 mA, whereas base current changed from $$20 \ \mu A$$ to $$25 \ \mu A$$ value. If transistor is in active state, small signal current gain (current amplification factor) will be

A square wave of the modulating signal is shown in the figure. The carrier wave is given by $$C(t) = 5 \sin(8\pi t)$$ Volt. The modulation index is