Mock Test 1 — Electrostatics

The force between two charges in vacuum is $F$. In a medium with $\epsilon_r = 4$, force becomes:

The electric flux through a Gaussian cube of side $a$ containing charge $+Q$ at one corner:

A dipole in uniform field experiences:

Two point charges $+4\,\mu$C and $+9\,\mu$C are $10$ cm apart. Position of null point from $+4\,\mu$C:

Capacitors of $2$ and $3\,\mu$F in series; combination in parallel with $5\,\mu$F. Total:

The potential energy of two charges $+q$ each at distance $r$ apart:

The capacitance of a parallel plate capacitor doubles if:

The work done to move a charge $q$ along a path from A to B where $V_A = 10$ V, $V_B = 4$ V:

A solid conducting sphere of charge $Q$, radius $R$ has electric field inside:

The energy density of electric field $E$ in vacuum:

Two $1\,\mu$F capacitors in parallel, then series with $0.5\,\mu$F. Equivalent in $\mu$F (rounded):

Three charges of $+1\,\mu$C each at corners of an equilateral triangle of side $1$ m. PE of system in $10^{-2}$ J (rounded):

A parallel plate capacitor of $20$ pF charged to $100$ V. Charge stored in $10^{-9}$ C:

Assertion (A): The electric field inside a conductor is zero. Reason (R): Free charges redistribute on the surface until the inside field becomes zero.

Assertion (A): Capacitance of a capacitor with a dielectric is greater than without. Reason (R): Dielectric reduces the effective field, allowing more charge for the same voltage.