JEE Main entrance exam Question Bank Solutions for Physics (JEE Main)

A small toy starts moving from the position of rest under constant acceleration. If it travels a distance of 10 minutes, the distance travelled by the toy in the next will be ______.

Two vectors `vec"A"` and `vec"B"` have equal magnitudes. If magnitude of `vec"A"` + `vec"B"` is equal to two times the magnitude of `vec"A"` - `vec"B"`, then the angle between  `vec"A"` and `vec"B"` will be :

A person can throw a ball up to a maximum range of 100 m. How high above the ground he can throw the same ball?

A radioactive material decays by simultaneous emissions of two particles with half-lives of 1400 years and 700 years respectively. What will be the time after which one-third of the material remains? (Take In3 = 1.1)

The amplitude of wave disturbance propagating in the positive x-direction given is by `1/(1 + x)^2` at time t = 0 and `1/(1 + (x - 2)^2)` at t = 1 s, where x and y are in 2 metres. The shape of wave does not change during the propagation. The velocity of the wave will be ______ m/s.

A series LCR circuit driven by 300 V at a frequency of 50 Hz contains a resistance R = 3 kΩ, an inductor of inductive reactance X_L = 250 πΩ, and an unknown capacitor. The value of capacitance to maximize the average power should be ______.

The initial mass of a rocket is 1000 kg. Calculate at what rate the fuel should be burnt so that the rocket is given an acceleration of 20 ms^-2. The gases come out at a relative speed of 500 ms^-1 with respect to the rocket.

The position of a particle is x - y plane is described by the variables x = at³ and y = 2at. Then the acceleration of the particle ______.

In SI units, the dimensions of `sqrt((ε_0)/(mu_0))` is ______.

A series LCR circuit containing a resistance of 120 Ω has angular resonance frequency 4 × 10⁵ rad s^-1. At resonance the voltage across resistance and inductance are 60 V and 40 V respectively. At what frequency the current in the circuit lags the voltage by 45°. Give answer in ______ × 10⁵ rad s^-1.

In the figure, the optical fibre is l = 2 m long and has a diameter of d = 20 µm. If a ray of light is incident on one end of the fibre at angle θ₁ = 40°, the number of reflections it makes before emerging from the other end is close to:

(Refractive index of fibre is 1.31 and sin 40° = 0.64)

The count rate of activity of a radioactive sample of a very large population decreased from 1024 to 128 in 3 minutes. Then the rate of disintegration at the end of 5 minutes is ______.

A particle of mass 10^-2 kg is moving along the positive x-axis under the influence of a force F(x) = `-"K"/(2x)^2` where K = 10^-2 Nm².  At time t = 0 it is at x = 1.0 m and its velocity is v = 0. The velocity of particle will be ______ m/s, when it reaches x = 0.50 m.

Two radioactive sources A and B of half lives of 1 hour and 2 hours, respectively, initially contain the same number of radioactive atoms. At the end of two hours, their rates of disintegration are in the ratio of ______.

The region between two concentric spheres of radii a < b contain volume charge density ρ(r) = `"c"/"r"`, where c is constant and r is radial- distanct from centre no figure needed. A point charge q is placed at the origin, r = 0. Value of c is in such a way for which the electric field in the region between the spheres is constant (i.e. independent of r). Find the value of c:

Which of the following physical quantities has neither dimensions nor unit?

Boat travels upstream in a river and at t = 0 a wooden cork is thrown over the side with zero initial velocity. After 7.5 minutes the boat turns and starts moving downstream catches the cork when it has drifted 1 km downstream. Then the velocity of water current is ______.

A glass slab of thickness 4 cm contains the same number of waves as 5 cm of water. When both are traversed by the same monochromatic light. If the refractive index of water is `(4/3)`. What is that of glass?

A wave of frequency υ = 1000 Hz, propagates at a velocity v = 700 m/sec along x-axis. Phase difference at a given point x during a time interval M = 0.5 × 10^-3 sec is ______.

A glass capillary sealed at the upper end is of length 0.11 m and internal diameter 2 × 10^-5 m. This tube is immersed vertically into a liquid of surface tension 5.06 × 10^-2 N/m. When the length x × 10^-2 m of the tube is immersed in liquid then the liquid level inside and outside the capillary tube becomes the same, then the value of x is ______ m. (Assume atmospheric pressure is 1.01 × 105 `"N"/"m"^2`)