JEE Main Physics Mock Test- 8 - JEE MCQ

Two bodies of mass 10 kg and 5 kg moving in concentric orbits of radii R and r such that their periods are the same. Then the ratio between their centripetal acceleration is

An electric dipole is placed along the X-axis at the origin O. A point P is at a distance of 20 cm from this origin such that OP makes an angle π/3 with the X axis. If electric field at P makes an angle θ with X-axis, the value of θ is

A semi circle arc of radius 'a' is charged uniformly and the charge per unit length is λ. The electric field at its centre is

The figure shows the symbol of a

Which of the following equations is definitely wrong?

A 2 kg mass is rotating on a circular path of radius 0.8 m with angular velocity of 44 rad-s^-1. If radius of the path becomes 1 m, then value of angular velocity will be

For a gas, if the ratio of specific heats at constant pressure and volume is γ, then the value of degree of freedom is

Which is not a unit of electric field

In a mixture of H−He⁺ gas (He⁺ is singly ionized He atom) , H atoms and He⁺ ions are excited to their respective first excited states. Subesquently, H atoms transfer their total excitation energy to He⁺ ions (by collisions). Assume that the Bohr model of atom is exactly vaild.

Q. The quantum number n of the state finally populated in He⁺ ions is

A biconvex thin lens is prepared from glass of refractive index µ₂ = 3/2. The two converging surface have equal radii of  20cm each. One of the surface is silvered from outside to make it reflecting. It is placed in a medium of refractive index µ₁ = 5/3. This system will behave as concave mirror of focal length f, find value of |f| in cm.

Find the maximum kinetic energy (in eV) of the photoelectron liberated from the surface of lithium (work function φ = 2.15eV) by electromagnetic radiation whose electric component varies with time as E = a (1 + cos ωt)cosω₀t, 
where a is a constant, ω = 12 × 10¹⁴ rads^–1 and ω₀ =  3.6 × 10¹⁵ rads^–1 (h = 6.6 × 10^–34 in SI units)

A photosensitive surface is irradiated with light of wavelength λ, the stopping potential is V. When the same surface is irradiated with the light of wavelength 2λ, stopping potential is V/3. Then the ratio of threshold wavelength (λ_max) and the λ is

One of the circuits for the measurement of resistance by potentiometer is shown. The galvanometer is connected at point A and zero deflection is observed at length PJ = 30 cm. In second case the secondary cell is changed. Take E_S = 10 V and r = 1Ω  in 1^st reading and E_S = 5V and r = 2Ω in 2^nd reading. In second case, the zero deflection is observed at length PJ = 10 cm. What is the resistance R (in ohm)?

A uniform triangular plate of triangular area 1m², base length 60 cm and thickness 10 mm (prism like shape) is lying vertically on a smooth ground as shown in figure. Find maximum value of cotθ for which it does not topple.