NTA JEE Main 28th July 2022 Shift 1

A wire of resistance $$R_1$$ is drawn out so that its length is increased by twice of its original length. The ratio of new resistance to original resistance is:

The current sensitivity of a galvanometer can be increased by:
(A) decreasing the number of turns
(B) increasing the magnetic field
(C) decreasing the area of the coil
(D) decreasing the torsional constant of the spring
Choose the most appropriate answer from the options given below:

As shown in the figure, a metallic rod of linear density 0.45 kg m$$^{-1}$$ is lying horizontally on a smooth incline plane which makes an angle of 45° with the horizontal. The minimum current flowing in the rod required to keep it stationary, when 0.15 T magnetic field is acting on it in the vertical upward direction, will be (Use $$g = 10$$ m s$$^{-2}$$)

The equation of current in a purely inductive circuit is $$5\sin(49\pi t - 30°)$$. If the inductance is 30 mH then the equation for the voltage across the inductor, will be

As shown in the figure, after passing through the medium 1, the speed of light $$v_2$$ in medium 2 will be: (Given $$c = 3 \times 10^8$$ m s$$^{-1}$$)

In normal adjustment, for a refracting telescope, the distance between objective and eye piece is 30 cm. The focal length of the objective, when the angular magnification of the telescope is 2, will be:

The equation $$\lambda = \frac{1.227}{x}$$ nm can be used to find the de-Broglie wavelength of an electron. In this equation $$x$$ stands for:
Where, $$m$$ = mass of electron, $$P$$ = momentum of electron, $$K$$ = Kinetic energy of electron, $$V$$ = Accelerating potential in volts for electron

The half life period of a radioactive substance is 60 days. The time taken for $$\frac{7}{8}$$th of its original mass to disintegrate will be:

Identify the solar cell characteristics from the following options:

In the case of amplitude modulation to avoid distortion the modulation index $$\mu$$ should be: