CBSE Class 12 Electric Charges and Fields — practice questions
62 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 12 Electric Charges and Fields in the app →Two point charges of $+2\ \mu$C and $+3\ \mu$C are placed $30$ cm apart. The Coulomb force between them is:A point charge of $5\ \mu$C is placed at the origin. The electric field magnitude at $0.5$ m is:A dipole consists of $+q$ and $-q$ separated by distance $d$. Its dipole moment direction is:A closed surface encloses a net charge of $4\ \mu$C. The total electric flux through the surface is:The smallest charge that can exist freely in nature isTwo point charges $q_1$ and $q_2$ separated by distance $r$ in vacuum attract each other with force $F$. If boThe principle of SUPERPOSITION for electric forces states that the net force on a charge due to multiple otherAn electric dipole of dipole moment $\vec{p}$ is placed in a UNIFORM electric field $\vec{E}$. The torque expeThe electric field at a distance $r$ from a POINT charge $q$ (in vacuum) has magnitudeGauss's law in integral form states that the electric flux through a CLOSED surface equalsThe electric field just OUTSIDE a uniformly charged conducting sphere of total charge $Q$ and radius $R$, at aInside a uniformly charged conducting sphere (in equilibrium), the electric field isTwo identical small spheres carry charges $+10\,\mu\text{C}$ each and are placed $30\,\text{cm}$ apart in vacuAn ELECTRIC DIPOLE consists of charges $+q$ and $-q$ separated by a small displacement $2a$. The dipole momentThe electric field due to an INFINITELY long straight uniformly charged wire (linear charge density $\lambda$)The electric field due to an INFINITE plane sheet of uniform surface charge density $ igma$ (in vacuum) isIf a charge $q$ is placed in a medium of dielectric constant $K$ instead of vacuum, the Coulomb force between Which property is TRUE for electric field LINES?Two charges of the same kind brought together will:Two charges of opposite kinds brought together will:A charged body far smaller than the distances involved is treated as a:For a point charge, all the charge is assumed concentrated at:Charges in a system are combined by adding them:Electric charges add up in the same way as:Charge is like mass in having magnitude but no:Unlike mass, an electric charge may also be:Conservation of charge has been established by:All free charges are integral multiples of a basic unit written:The basic unit of charge is the charge carried by a proton or:By convention, the charge on an electron is taken as:Charge coming only in whole multiples of e is called:Quantisation of charge was first suggested by the laws of:Quantisation of charge was demonstrated experimentally by:Millikan demonstrated the quantisation of charge in the year:The SI unit of electric charge is the:One coulomb is the charge flowing in one second at a current of:Coulomb measured the force between charges using a balance that is:The torsion balance was later used to measure gravity by:Touching a charged sphere to an identical uncharged one leaves each:Adding the forces from several charges one by one uses the principle of:The discovery that rubbed amber attracts light objects is credited to:The word electricity comes from the Greek word elektron, meaning:Thales of Miletus made his observation about amber around:A metal rod held in the hand and rubbed with wool shows:A neutral pith ball joined by copper wire to a negative rod acquires a charge that is:Substances that let electricity pass through them easily are called:Conductors contain electrons that are comparatively:Which of these is listed as a conductor?Glass, porcelain, plastic and wood are examples of:Charge transferred to a conductor readily gets:Charge placed on an insulator:The effects of positive and negative charge tend to:Charged bodies much smaller than their separation are treated as:Charges add up like:Charge has magnitude but no:Unlike charge, the mass of a body is always:The total charge of a system with charges +1, +2, -3, +4 and -5 units is:When two bodies are rubbed, what one body gains in charge the other:The total charge of an isolated system is always:When a neutron turns into a proton and an electron, the total charge is:Free charges come in integral multiples of a basic unit written as:Coulomb found the force between two point charges varies inversely as the: