Physics Current Electricity

A copper wire of length 10m and radius $\left({10}^{-2}/\pi \right)\mathrm{m}$ has electrical resistance of $10\mathrm{\Omega }$ . The current density in the wire for an electric field strength of $10(\mathrm{V}/\mathrm{m})$  is:

Two resistors of resistance, $$ $100\mathrm{\Omega }$ and $200\mathrm{\Omega }$ $$ are connected in parallel in an electrical circuit. The ratio of the thermal energy developed in $100\mathrm{\Omega }$ $$ to that in $100\mathrm{\Omega }$ $$ in a given time is :

Resistance of a carbon resistor determined from colour codes is $(22000\pm 5\mathrm{\%})\mathrm{\Omega }$ The colour of third band must be:

If the galvanometer $G$ does not show any deflection in the circuit shown, the value of $\mathrm{R}$ is given by:

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As the temperature increases, the electric resistance:

The magnitude and direction of the current in the following circuit is

Two wires of same length and thickness having specific resistance 6 Ω cm and 3 Ω cm respectively are connected in parallel. The effective resistivity is ρ Ω cm. The value of ρ, to the nearest integer, is.

Consider a 72 cm long wire AB as shown in the figure. The galvanometer jockey is placed at P on AB at a distance x cm from A. The galvanometer shows zero deflection.

The value of x, to nearest integer, is.

The voltage across the 10Ω resistor in the given circuit is x volt. The value of 'x' to the nearest integer is ----------.

Sea-water at a frequency f = 9 * 10² Hz, has permittivity ε = 80ε₀ and resistivity ρ = 0.25Ωm. Imagine a parallel plate capacitor is immersed in seawater and is driven by an alternating voltage source V(t) = V₀sin(2πft). Then the conduction current density become 10ˣ times the displacement current density after time t = 1/800 s. The value of x is ______. [Given: 1/(4πε₀) = 9 * 10⁹ Nm²C⁻²]