Physics M.C.Q (1 Marks)

A capacitor having capacitance  C is charged to a voltage V. It is then removed and connected in parallel with another identical capacitor which is uncharged. The new charge on each capacitor is now(a) CV(b) CV / 2(c) 2 CV   (d) CV / 4

Three capacitors each of 6μF  are available. The minimum and maximum capacitances which may be obtained are(a) 6 μF, 18 μF(b) 3 μF, 12 μF(c) 2 μF, 12 μF(d) 2 μF, 18 μF

A 4 μF  condenser is connected in parallel to another condenser of 8 μF. Both the condensers are then connected in series with a 12 μF  condenser and charged to 20 volts. The charge on the plate of 4 μF condenser is(a) 3.3 μC(b) 40 μC(c) 80 μC(d) 240 μC

Two capacitors each of capacity 2 μF  are connected in parallel. This system is connected in series with a third capacitor of 12 μF  capacity. The equivalent capacity of the system will be(a) 16 μF                                            (b) 13 μF(c) 4 μF   (d) 3 μF

A parallel plate capacitor is made by stacking n equally spaced plates connected alternately. If the capacitance between any two plates is  C then the resultant capacitance is(a) C(b) nC (c) (n – 1)C(d) (n + 1)C

Two capacitors of equal capacity are first connected in parallel and then in series. The ratio of the total capacities in the two cases will be(a) 2 : 1(b) 1 : 2(c) 4 : 1(d) 1 : 4

A condenser of capacitance 10 μF has been charged to 100 volts. It is now connected to another uncharged condenser in parallel. The common potential becomes 40 volts. The capacitance of another condenser is(a) 15 μF (b) 5 μF(c) 10 μF(d) 16.6 μF

Three capacitances of capacity 10 μF, 5 μF  and 5 μF  are connected in parallel. The total capacity will be(a) 10 μF  (b) 5 μF(c) 20 μF(d) None of the above

Two capacitors each of 1μF capacitance are connected in parallel and are then charged by 200 volts  d.c. supply. The total energy of their charges (in joules) is(a) 0.01(b) 0.02(c) 0.04(d) 0.06

A capacitor is charged to 200 volt it has 0.1 coulomb charge. When it is discharged, energy will be(a) 1 J(b) 4 J(c) 10 J(d) 20 J

The potentials of the two plates of capacitor are +10V and –10 V. The charge on one of the plates is 40 C. The capacitance of the capacitor is(a) 2 F(b) 4 F(c) 0.5 F(d) 0.25 F

If the distance between the plates of parallel plate capacitor is halved and the dielectric constant of dielectric is doubled, then its capacity will(a) Increase by 16 times(b) Increase by 4 times(c) Increase by 2 times(d) Remain the same

When a lamp is connected in series with capacitor, then(a) Lamp will not glow(b) Lamp will burst out(c) Lamp will glow normally(d) None of these

When a dielectric material is introduced between the plates of a charges condenser, then electric field between the plates (a) Remain constant(b) Decreases(c) Increases(d) First increases then decreases

On increasing the plate separation of a charged condenser, the energy(a) Increases(b) Decreases(c) Remains unchanged(d) Becomes zero

An air filled parallel plate capacitor has capacity C. If distance between plates is doubled and it is immersed in a liquid then capacity becomes twice. Dielectric constant of the liquid is(a) 1 (b) 2(c) 3(d) 4

If a dielectric substance is introduced between the plates of a charged air-gap capacitor. The energy of the capacitor will(a) Increase(b) Decrease(c) Remain unchanged(d) First decrease and then increase

If eight identical drops are joined to form a bigger drop, the potential on bigger as compared to that on smaller drop will be(a) Double(b) Four times(c) Eight times(d) One time

64 drops of mercury each charged to a potential of 10V. They are combined to form one bigger drop. The potential of this drop will be (Assume all the drops to be spherical)(a) 160 V(b) 80 V(c) 10 V   (d) 640 V

The unit of electric permittivity is

A 10 micro-farad capacitor is charged to 500 V and then its plates are joined together through a resistance of 10 ohm. The heat produced in the resistance is(a) 500 J  (b) 250 J(c) 125 J  (d) 1.25 J

Capacitance of a parallel plate capacitor becomes 4/3 times its original value if a dielectric slab of thickness t = d/2 is inserted between the plates (d is the separation between the plates). The dielectric constant of the slab is(a) 8 (b) 4(c) 6  (d) 2

A parallel plate air capacitor is charged and then isolated. When a dielectric material is inserted between the plates of the capacitor, then which of the following does not change(a) Electric field between the plates(b) Potential difference across the plates(c) Charge on the plates(d) Energy stored in the capacitor

A capacitor of capacitance 6μF  is charged upto 100 volt. The energy stored in the capacitor is(a) 0.6 Joule(b) 0.06 Joule(c) 0.03 Joule(d) 0.3 Joule