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

When a clock is viewed in a mirror, the needles exhibit a time which appears to be 8:20. Then the actual time will be:

An upright object is placed at a distance of 40 cm in front of a convergent lens of a focal length of 20 cm. A convergent mirror of focal length 10 cm is placed at a distance of 60 cm on the other side of the lens. The position and size of the final image will be ______.

Two plane mirrors are inclined at an angle of 40°. The possible number of images of an object placed at point P would be?

A point object is placed at a distance of 30 cm from a convex mirror of a focal length of 30 cm. What is the separation between the image and the object?

A convex lens of focal length 15 cm is placed coaxially in front of a convex mirror. The lens is 5 cm from the pole of the mirror. When an object is placed on the axis at a distance of 20 cm from the lens, it is found that the image coincides with the object. Calculate the radius of curvature of the mirror - (consider all-optical event): 

The electric field in a region is given by `vec"E"` = (Ax + B) `hat"i"`, where E is in NC^-1 and x is in metres. The values of constants are A = 20 SI unit and B = 10 SI unit. If the potential at x = 1 is V₁ and that at x = -5 is V₂, then V₁ - V₂ is ______.

A bar magnet having a magnetic moment of 2.0 × 10⁵ JT^-1, is placed along the direction of uniform magnetic field of magnitude B = 14 × 10^-5 T. The work done in rotating the magnet slowly through 60° from the direction of field is ______.

A bar magnet of length 6 cm has a magnetic moment of 4JT^-1 Find the strength of magnetic field at a distance of 200 cm from the centre of the magnet along its equatorial line.

The graph of ln `("R"/"R"_0)` versus ln A (R = radius of a nucleus and A = its mass number) is ______.

An RC Circuit as shown in the figure is driven by a AC source generating a square wave. The output wave pattern monitored by CRO would look close to:

The angle of deviation through a prism is minimum when

1. Incident rays and emergent rays are symmetric to the prism.
2. The refracted ray inside the prism becomes parallel to its base.
3. The angle of incidence is equal to that of the angle of emergence.
4. When the angle of emergence has doubled the angle of incidence.

Choose the correct answer from the options given below:

Magnetic materials used for making permanent magnets (P) and magnets in a transformer (T) have different properties of the following, which property best matches for the type of magnet required ?

One cubic plate, having a 15 cm side, floats on water surface. If surface tension of water is 60 dyne/cm. To lift this plate from water, Find the extra force required against weight.

The dispersive powers of flint glass and crown glass are 0.053 and 0.034, respectively and their mean refractive indices are 1.68 and 1.53 for white light. Calculate the angle of the flint glass prism required to form an achromatic combination with a crown glass prism of refracting angle 4°:

dispersive power of crown glass? Given that µ_v = 1.5230, µ_r = 1.5145

A prism of refractive index `sqrt2` and refracting angle A produces minimum deviation δ_m of a ray on one face at an angle of incidence 45°, The values of A and δ_m are, respectively ______.

Which of the following statements are correct?

1. Electric monopoles do not exist whereas magnetic monopoles exist.
2. Magnetic field lines due to a solenoid at its ends and outside cannot be completely straight and confined.
3. Magnetic field lines are completely confined within a toroid.
4. Magnetic field lines inside a bar magnet are not parallel.
5. χ = -1 is the condition for a perfect diamagnetic material, where x is its magnetic susceptibility.

The susceptibility of a paramagnetic material is 99. The permeability of the material in Wb/A-m is ______.

[permeability of the free space μ₀ = 4π × 10^-7 Wb/A - m]

The value of aluminium susceptibility is 2.2 × 10^-5. The percentage increase in the magnetic field if space within a current carrying toroid is filled with aluminium is  `"x"/10^4`. Then the value of x is ______.

A telegraph line of length 100 km has a capacity of 0.01 µF/ km and it carries an alternating current at 0.5 kilo cycle per second. If minimum impedance is required, then the value of the inductance that needs to be introduced in series is ______ mH. (if π = `sqrt10`)