Science (English Medium) Class 12 - CBSE Question Bank Solutions for Physics

How does the electric flux due to a point charge enclosed by a spherical Gaussian surface get affected when its radius is increased?

Write Maxwell's generalization of Ampere's circuital law. Show that in the process of charging a capacitor, the current produced within the plates of the capacitor is `I=varepsilon_0 (dphi_E)/dt,`where Φ_E is the electric flux produced during charging of the capacitor plates.

Write Maxwell's generalization of Ampere's circuital law. Show that in the process of charging a capacitor, the current produced within the plates of the capacitor is `I=varepsilon_0 (dphi_E)/dt,`where Φ_E is the electric flux produced during charging of the capacitor plates.

Calculate the de-Broglie wavelength of the electron orbitting in the n = 2 state of hydrogen atom.

Draw the circuit diagram of a full wave rectifier. Explain its working showing its input and output waveforms.

Briefly explain how the output voltage/current is unidirectional.

State Ampere’s circuital law.

Electron drift speed is estimated to be of the order of mm s⁻¹. Yet large current of the order of few amperes can be set up in the wire. Explain briefly.

Define electric flux.

Write S.I unit of electric flux.

Find out the outward flux to a point charge +q placed at the centre of a cube of side ‘a’. Why is it found to be independent of the size and shape of the surface enclosing it? Explain.

The equivalent wavelength of a moving electron has the same value as that of a photon of energy 6 × 10^–17 J. Calculate the momentum of the electron.

In a given coil of self-inductance of 5 mH, current changes from 4 A to 1 A in 30 ms. Calculate the emf induced in the coil.

"The outward electric flux due to charge +Q is independent of the shape and size of the surface which encloses is." Give two reasons to justify this statement.

What is the electric flux through a cube of side 1 cm which encloses an electric dipole?

Given the electric field in the region `vecE=2xhati`, find the net electric flux through the cube and the charge enclosed by it.

Given a uniform electric field `vecE=5xx10^3hati`N/C, find the flux of this field through a square of 10 cm on a side whose plane is parallel to the y-z plane. What would be the flux through the same square if the plane makes a 30° angle with the x-axis ?

Draw the circuit diagram of a half wave rectifier and explain its working.

Consider two hollow concentric spheres, S₁ and S₂, enclosing charges 2Q and 4Q respectively as shown in the figure. (i) Find out the ratio of the electric flux through them. (ii) How will the electric flux through the sphere S₁ change if a medium of dielectric constant 'εr' is introduced in the space inside S₁ in place of air ? Deduce the necessary expression

Consider a uniform electric field E = 3 × 10³ `bbhat i` N/C.

1. What is the flux of this field through a square of 10 cm on a side whose plane is parallel to the yz plane?
2. What is the flux through the same square if the normal to its plane makes a 60° angle with the x-axis?