NTA JEE Main 27th August 2021 Shift 1 - Physics

The resultant of these forces $$\vec{OP}, \vec{OQ}, \vec{OR}, \vec{OS}$$ and $$\vec{OT}$$ is approximately ______ N.
[Take $$\sqrt{3} = 1.7, \sqrt{2} = 1.4$$. Given $$\hat{i}$$ and $$\hat{j}$$ unit vectors along $$x, y$$ axis]

If $$E$$ and $$H$$ represents the intensity of electric field and magnetizing field respectively, then the unit of $$\frac{E}{H}$$ will be:

Which of the following is not a dimensionless quantity?

A huge circular arc of length 4.4 ly subtends an angle 4s at the centre of the circle. How long it would take for a body to complete 4 revolution if its speed is 8 AU per second?
Given : 1 ly = $$9.46 \times 10^{15}$$ m
1 AU = $$1.5 \times 10^{11}$$ m

Moment of inertia of a square plate of side $$l$$ about the axis passing through one of the corner and perpendicular to the plane of square plate is given by:

In Millikan's oil drop experiment, what is viscous force acting on an uncharged drop of radius $$2.0 \times 10^{-5}$$ m and density $$1.2 \times 10^3$$ kg m$$^{-3}$$? Take viscosity of liquid = $$1.8 \times 10^{-5}$$ N s m$$^{-2}$$. (Neglect buoyancy due to air).

An ideal gas is expanding such that $$PT^3$$ = constant. The coefficient of volume expansion of the gas is:

A balloon carries a total load of 185 kg at normal pressure and temperature of 27°C. What load will the balloon carry on rising to a height at which the barometric pressure is 45 cm of Hg and the temperature is -7°C. Assuming the volume constant?

The variation of displacement with time of a particle executing free simple harmonic motion is shown in the figure.

The potential energy $$U(x)$$ versus time $$(t)$$ plot of the particle is correctly shown in figure:

A uniformly charged disc of radius $$R$$ having surface charge density $$\sigma$$ is placed in the $$xy$$ plane with its center at the origin. Find the electric field intensity along the $$z$$-axis at a distance $$Z$$ from origin:

Calculate the amount of charge on capacitor of 4 $$\mu$$F. The internal resistance of battery is 1$$\Omega$$:

Five identical cells each of internal resistance 1 $$\Omega$$ and emf 5 V are connected in series and in parallel with an external resistance $$R$$. For what value of $$R$$, current in series and parallel combination will remain the same?

Two ions of masses 4 amu and 16 amu have charges +2e and +3e respectively. These ions pass through the region of the constant perpendicular magnetic field. The kinetic energy of both ions is the same. Then:

A bar magnet is passing through a conducting loop of radius $$R$$ with velocity $$v$$. The radius of the bar magnet is such that it just passes through the loop. The induced e.m.f. in the loop can be represented by the approximate curve:

The electric field in a plane electromagnetic wave is given by, $$E = 50\sin(500x - 10 \times 10^{10}t)$$ V m$$^{-1}$$. The velocity of an electromagnetic wave in this medium is: (Given $$c$$ = the speed of light in vacuum).

An object is placed beyond the centre of curvature $$C$$ of the given concave mirror. If the distance of the object is $$d_1$$ from $$C$$ and the distance of the image formed is $$d_2$$ from $$C$$, the radius of curvature of this mirror is:

Find the distance of the image from object $$O$$, formed by the combination of lenses in the figure:

In a photoelectric experiment, increasing the intensity of incident light:

There are $$10^{10}$$ radioactive nuclei in a given radioactive element. Its half-life time is 1 min. How many nuclei will remain after 30 s? $$(\sqrt{2} = 1.414)$$

For a transistor in CE mode to be used as an amplifier, it must be operated in:

If the velocity of a body related to displacement $$x$$ is given by $$v = \sqrt{5000 + 24x}$$ m s$$^{-1}$$, then the acceleration of the body is _________ m s$$^{-2}$$.

Two persons $$A$$ and $$B$$ perform same amount of work in moving a body through a certain distance $$d$$ with application of forces acting at angles 45° and 60° with the direction of displacement respectively. The ratio of force applied by person $$A$$ to the force applied by person $$B$$ is $$\frac{1}{\sqrt{x}}$$. The value of $$x$$ is _________.

A body of mass $$(2M)$$ splits into four masses $$\{m, M-m, m, M-m\}$$, which are rearranged to form a square as shown in the figure. The ratio of $$\frac{M}{m}$$ for which, the gravitational potential energy of the system becomes maximum is $$x : 1$$. The value of $$x$$ is _________.

A rod $$CD$$ of thermal resistance $$10.0$$ KW$$^{-1}$$ is joined at the middle of an identical rod $$AB$$ as shown in figure. The ends $$A$$, $$B$$ and $$D$$ are maintained at 200°C, 100°C and 125°C respectively. The heat current in $$CD$$ is _________ P W. The value of $$P$$ is _________.

Two cars $$X$$ and $$Y$$ are approaching each other with velocities 36 km h$$^{-1}$$ and 72 km h$$^{-1}$$ respectively. The frequency of a whistle sound as emitted by a passenger in car $$X$$, heard by the passenger in car $$Y$$ is 1320 Hz. If the velocity of sound in air is 340 ms$$^{-1}$$, the actual frequency of the whistle sound produced is _________ Hz.

First, a set of $$n$$ equal resistors of 10 $$\Omega$$ each are connected in series to a battery of E.M.F. 20 V and internal resistance 10 $$\Omega$$. A current $$I$$ is observed to flow. Then, the $$n$$ resistors are connected in parallel to the same battery. It is observed that the current is increased 20 times, then the value of $$n$$ is _________.

A uniform conducting wire of length is 24$$a$$, and resistance $$R$$ is wound up as a current carrying coil in the shape of an equilateral triangle of side $$a$$ and then in the form of a square of side $$a$$. The coil is connected to a voltage source $$V_0$$. The ratio of magnetic moment of the coils in case of equilateral triangle to that for square is $$1 : \sqrt{y}$$ where $$y$$ is _________.

The alternating current is given by, $$i = \left\{\sqrt{42}\sin\left(\frac{2\pi}{T}t\right) + 10\right\}$$ A. The R.M.S. value of this current is _________ A.

A circuit is arranged as shown in figure. The output voltage $$V_o$$ is equal to _________ V.

A transmitting antenna has a height of 320 m and that of receiving antenna is 2000 m. The maximum distance between them for satisfactory communication in line of sight mode is $$d$$. The value of $$d$$ is _________ km.