Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Physics

Answer the following question.
State Gauss's law for magnetism. Explain its significance.

Three circuits, each consisting of a switch 'S' and two capacitors, are initially charged, as shown in the figure. After the switch has been closed, in which circuit will the charge on the left-hand capacitor
(i) increase,
(ii) decrease, and
(iii) remains the same? Give reasons.

State Gauss's law in electrostatics. Show, with the help of a suitable example along with the figure, that the outward flux due to a point charge 'q'. in vacuum within a closed surface, is independent of its size or shape and is given by `q/ε_0`

State Gauss’s law on electrostatics and drive expression for the electric field due to a long straight thin uniformly charged wire (linear charge density λ) at a point lying at a distance r from the wire.

The variation of inductive reactance (X_L) of an inductor with the frequency (f) of the ac source of 100 V and variable frequency is shown in fig.

1. Calculate the self-inductance of the inductor.
2. When this inductor is used in series with a capacitor of unknown value and a resistor of 10 Ω at 300 s^–1, maximum power dissipation occurs in the circuit. Calculate the capacitance of the capacitor.

Obtain the expression for capacitance for a parallel plate capacitor.

The Gaussian surface ______.

A capacitor is charged by a battery. The battery is removed and another identical uncharged capacitor is connected in parallel. The total electrostatic energy of resulting system ______.

The positive terminal of 12 V battery is connected to the ground. Then the negative terminal will be at ______.

1. Charge on each capacitor remains same and equals to the main charge supplied by the battery.
2. Potential difference and energy distribute in the reverse ratio of capacitance.
3. Effective capacitance is even les than the least of teh individual capacitances.

The work done in placing a charge of 8 × 10^–18 coulomb on a condenser of capacity 100 micro-farad is ______.

The surface considered for Gauss’s law is called ______.