Join WhatsApp Icon JEE WhatsApp Group

NTA JEE Main 25th January 2023 Shift 1 - Physics

For the following questions answer them individually

Match List I with List II
List - I                        List - II
A. Surface tension       I. kg m$$^{-1}$$ s$$^{-1}$$
B. Pressure                 II. kg m s$$^{-1}$$
C. Viscosity                III. kg m$$^{-1}$$ s$$^{-2}$$
D. Impulse                  IV. kg s$$^{-2}$$
Choose the correct answer from the options given below:

A car is moving with a constant speed of 20 m s$$^{-1}$$ in a circular horizontal track of radius 40 m. A bob is suspended from the roof of the car by a massless string. The angle made by the string with the vertical will be: (Take g = 10 m s$$^{-2}$$)

An object of mass 8 kg is hanging from one end of a uniform rod $$CD$$ of mass 2 kg and length 1 m, is pivoted at its end $$C$$ on a vertical wall as shown in the figure. It is supported by a cable $$AB$$ such that the system is in equilibrium. The tension in the cable is: (Take $$g = 10$$ m s$$^{-2}$$)

image

Assume that the earth is a solid sphere of uniform density and a tunnel is dug along its diameter throughout the earth. It is found that when a particle is released in this tunnel, it executes a simple harmonic motion. The mass of the particle is 100 g. The time period of the motion of the particle will be (approximately) (take $$g = 10$$ ms$$^{-2}$$, radius of earth = 6400 km)

A parallel plate capacitor has plate area 40 cm$$^2$$ and plates separation 2 mm. The space between the plates is filled with a dielectric medium of a thickness 1 mm and dielectric constant 5. The capacitance of the system is:

A uniform metallic wire carries a current 2 A, when 3.4 V battery is connected across it. The mass of uniform metallic wire is $$8.92 \times 10^{-3}$$ kg, density is $$8.92 \times 10^3$$ kg m$$^{-3}$$ and resistivity is $$1.7 \times 10^{-8}$$ $$\Omega$$ - m. The length of wire is:

A solenoid of 1200 turns is wound uniformly in a single layer on a glass tube 2 m long and 0.2 m in diameter. The magnetic intensity at the center of the solenoid when a current of 2 A flows through it is:

All electromagnetic wave is transporting energy in the negative $$z$$ direction. At a certain point and certain time the direction of electric field of the wave is along positive $$y$$ direction. What will be the direction of the magnetic field of the wave at that point and instant?

In Young's double slits experiment, the position of 5$$^{th}$$ bright fringe from the central maximum is 5 cm. The distance between slits and screen is 1 m and wavelength of used monochromatic light is 600 nm. The separation between the slits is:

Electron beam used in an electron microscope, when accelerated by a voltage of 20 kV has a de-Broglie wavelength of $$\lambda_0$$. If the voltage is increased to 40 kV then the de-Broglie wavelength associated with the electron beam would be:

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: Photodiodes are used in forward bias usually for measuring the light intensity.
Reason R: For a $$p-n$$ junction diode, at applied voltage $$V$$ the current in the forward bias is more than the current in the reverse bias for $$|V_z| > \pm V \geq |V_0|$$ where $$V_0$$ is the threshold voltage and $$V_z$$ is the breakdown voltage.
In the light of the above statements, choose the correct answer from the options given below

If $$\vec{P} = 3\hat{i} + \sqrt{3}\hat{j} + 2\hat{k}$$ and $$\vec{Q} = 4\hat{i} + \sqrt{3}\hat{j} + 2.5\hat{k}$$, then, the unit vector in the direction of $$\vec{P} \times \vec{Q}$$ is $$\frac{1}{x}(\sqrt{3}\hat{i} + \hat{j} - 2\sqrt{3}\hat{k})$$. The value of $$x$$ is

Backspace
789
456
123
0.-
Clear All

An object of mass $$m$$ initially at rest on a smooth horizontal plane starts moving under the action of force $$F = 2$$ N. In the process of its linear motion, the angle $$\theta$$ (as shown in figure) between the direction of force and horizontal varies as $$\theta = kx$$, where $$k$$ is a constant and $$x$$ is the distance covered by the object from its initial position. The expression of kinetic energy of the object will be $$E = \frac{n}{k}\sin\theta$$. The value of $$n$$ is _____.

image
Backspace
789
456
123
0.-
Clear All

$$I_{CM}$$ is moment of inertia of a circular disc about an axis (CM) passing through its center and perpendicular to the plane of the disc. $$I_{AB}$$ is its moment of inertia about an axis AB perpendicular to the plane and parallel to the axis CM at a distance $$\frac{2}{3}R$$ from the center, where R is the radius of the disc. The ratio of $$I_{AB}$$ and $$I_{CM}$$ is $$x : 9$$. The value of $$x$$ is _____.

image
Backspace
789
456
123
0.-
Clear All

As shown in the figure, in an experiment to determine Young's modulus of a wire, the extension-load curve is plotted. The curve is a straight line passing through the origin and makes an angle of 45° with the load axis. The length of the wire is 62.8 cm and its diameter is 4 mm. The Young's modulus is found to be $$x \times 10^4$$ N m$$^{-2}$$. The value of $$x$$ is _____.

image
Backspace
789
456
123
0.-
Clear All

A uniform electric field of 10 N C$$^{-1}$$ is created between two parallel charged plates (as shown in figure). An electron enters the field symmetrically between the plates with a kinetic energy 0.5 eV. The length of each plate is 10 cm. The angle ($$\theta$$) of deviation of the path of electron as it comes out of the field is _____ (in degree).

Backspace
789
456
123
0.-
Clear All

A ray of light is incident from air on a glass plate having thickness $$\sqrt{3}$$ cm and refractive index $$\sqrt{2}$$. The angle of incidence of a ray is equal to the critical angle for glass-air interface. The lateral displacement of the ray when it passes through the plate is _____ $$\times 10^{-2}$$ cm. (given sin 15° = 0.26)

Backspace
789
456
123
0.-
Clear All

The wavelength of the radiation emitted is $$\lambda_0$$ when an electron jumps from the second excited state to the first excited state of hydrogen atom. If the electron jumps from the third excited state to the second orbit of the hydrogen atom, the wavelength of the radiation emitted will be $$\frac{20}{x}\lambda_0$$. The value of $$x$$ is _____.

Backspace
789
456
123
0.-
Clear All