ICSE Class 12 Physics — Important Questions 2026

Like charges attract each other.

The quantisation of electric charge means that q = ±ne, where n is a positive integer.

The value of Coulomb's constant k (= 1/4πε₀) in SI units is:

Two equal positive charges are placed 1 m apart in vacuum. If the distance is doubled, the electrostatic force becomes:

The magnification produced by a spherical mirror is given by m = -v/u. If the magnification is +0.5 for a mirror, what does this tell us about the image?

According to the New Cartesian Sign Convention, what sign is assigned to the focal length of a concave mirror?

An object is placed between the pole and focus of a concave mirror. What type of image is formed?

A convex mirror of focal length 15 cm produces an image that is 1/3 the size of the object. Using m = f/(f - u), what is the object distance?

A large plane sheet has surface charge density 1.77 × 10^-11 C·m^-2. Find the electric field near the sheet and the field between two such sheets carrying equal and opposite charge densities of this magnitude.

A conducting sphere of radius 0.30 m carries charge 2.7 μC. Find the electric field just outside the surface and the electric field inside the sphere.

A uniformly charged non-conducting sphere has radius 0.50 m and total charge 6.0 μC. Find the electric field at r = 0.20 m from the centre.

A cube encloses a charge of 1.5 μC at any position inside it. Find the total electric flux through the cube, and then the flux if a second charge of -0.5 μC is also enclosed.