Class 12th

An equi-concave lens of radius of curvature 15 cm and μ = 1.5 is placed in water (μ = 1.33). If one surface is silvered, then image distance from lens when an object is placed at distance of 14 cm from the lens is

A rod of length l slides against the perpendicular wall, such that the lowest point (A) of the rod slides with a speed v on horizontal surface as shown in figure. There exist a uniform magnetic field throughout the region. Now, what is the distance of point 'P' on the rod from end 'A' such that, the induced emf across 'P' and 'A' is maximum?

A simple LR circuit is connected to a battery at t = 0. The time instant at which rate of energy storage in inductor is half of power delivered by battery

Twenty seven drops of same size are charged at 220 V each. They combine to form a bigger drop. Calculate the potential of the bigger drop.

A positively charged particle of specific charge α, accelerated by a potential difference V moves through a uniform transverse magnetic field B. The field occupies a region of width l. The angle θ through which the charged particle deviates from initial direction of its motion is

A multi range current ammeter can be constructed by using a galvanometer circuit as shown in figure. We want a current meter that can measure 10 mA, 100 mA and 1A using a galvanometer of resistance 10 Ω and that produces maximum deflection for current 1 mA. Value of S₁ + S₂ + S₃ in ohms is

For the following logic circuit, the truth table is:

A dielectric slab of dielectric constants k is slowly inserted inside the parallel plate capacitor having plate area A and separation between plates d as shown in figure. If dimensions of dielectric slab is same as plates of capacitor and capacitor is connected through the battery, then work done by agent will be (C = ε₀ A/d)

The radius of inner most orbit of hydrogen atom is $5.3*{10}^{-11}\mathrm{m}$ . What is the radius of third allowed orbit of hydrogen atom?

A short dipole of dipole moment P is placed along x – axis at a distance d from a long wire having uniform linear charge density +λ (wire is along y – axis) as shown. Find minimum work required to align this dipole along y axis (so that dipole moment P is along +y direction)