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

The coefficient of static friction between a car's tires and a level road is 0.80. If the car is to be stopped in a maximum time of 3.0 s, its speed cannot exceed.

If momentum [P], area [A] and time [T] are taken as fundamental quantities, then the dimensional formula for coefficient of viscosity is ______.

A quantity x is by (IFv²/WL⁴) in term of moment of inertia I, force F, velocity v, work W and Length L. The dimensional formula for x is same as that of ______.

The trajectories of the two projectiles are shown in the figure. Let T₁ and T₂ be the time periods and u₁ and u₂ be their speeds of projection. Then ______.

Starting from rest, a body slides down a 45° inclined plane in twice the time it takes to slide down the same distance in the absence of friction. The coefficient of friction between the body and the inclined plane is ______.

If the magnetic lines of force are shaped like arcs of concentric circles with their centre at point O in a certain section of a magnetic field ______.

The radioactivity of an old sample of whisky due to tritium (half-life 12.5 years) was found to be only about 4% of that measured in a recently purchased bottle marked 10 years old. The age of a sample is ______ years.

An object is projected in the air with initial velocity u at an angle θ. The projectile motion is such that the horizontal range R, is maximum.

Another object is projected in the air with a horizontal range half of the range of first object. The initial velocity remains same in both the case. The value of the angle of projection, at which the second object is projected, will be ______ degree.

A ball is projected from the ground with a speed 15 ms^-1 at an angle θ with horizontal so that its range and maximum height are equal, then tan θ will be equal to ______.

The initial speed of a bullet fired from a rifle is 630 m/s. The rifle is fired at the centre of a target 700 m away at the same level as the target. How far above the centre of the target the rifle must be aimed in order to hit the target?

A block of mass 10 kg starts sliding on a surface with an initial velocity of 9.8 ms^-1. The coefficient of friction between the surface and bock is 0.5. The distance covered by the block before coming to rest is ______.

[use g = 9.8 ms^-2]

A body starts from rest on a long inclined plane of slope 45°. The coefficient of friction between the body and the plane varies as µ = 0.3 x, where x is distance travelled down the plane. The body will have maximum speed (for g = 10 m/s²) when x = ______.

The entropy of any system is given by `S = alpha^2betaIn[(mukR)/(Jbeta^2) + 3]` Where α and β are the constants µ J, k, and R are no. of moles, the mechanical equivalent of heat, Boltzmann constant, and gas constant respectively. `["take S" = (dQ)/T]`

Choose the incorrect option from the following.

The workdone by a gas molecule in an x' isolated system is given by, W = αβ² `e^(-x^2/(alpha"KT"))`, where x is the displacement, k is the Boltzmann constant and T is the temperature. α and β are constants. Then the dimensions of β will be ______.

The normal reaction 'N' for a vehicle of 800 kg mass, negotiating a turn on a 30° banked road at maximum possible speed without skidding is ______ × 10³ kg m/s².

[Given cos30° = 0.87, µ_s = 0.2]

A wave is represented by y = a sin(At - Bx + C) where A, B, C are constants and t is in seconds and x is in metre. The Dimensions of A, B, and C are ______.

A certain element decays in two different ways - it shows alpha decay with a half life of (ln 2) years and with beta decay, it has a half life of (ln 4) years. After how many years will a pure sample of 100 mg of the element would have 50 mg of that element?

An air bubble in glass slab (µ = 1.5) when viewed from one side, appears to be at 6 cm and from opposite side 4 cm. The thickness of glass slab is ______.

All the surfaces are frictionless. Strings are light and frictionless. The tension in string 1 is ______ N. (Take g = 10 m/s²)

A particle is given an initial speed u inside a smooth spherical shell of radius R = 1 m that it is just able to complete the circle. Acceleration of the particle when its velocity is vertical is ______.