Physics Current Electricity

What is the unit of electrical power?

A square shaped wire with resistance of each side   $3\Omega$  is bent to form a complete circle. The resistance between two diametrically opposite points of the circle in unit of   $\Omega$  will be________.

The ratio of the equivalent resistance of the network (shown in figure) between the points a and b when switch is open and switch is closed in x : 8. The value of x is_________.

First, a set of n equal resistors of 10 $\Omega$  each are connected in series to a battery of emf 20V and internal resistance 10 $\Omega$ . A current I is observed to flow. Then, the n resistors are connected in parallel to the same battery. It is observed that the current is increases 20 times, then the value of n is………

Two cells of same emf but different internal resistance r₁ and r₂ are connected in series with a resistance R. The value of resistance R, for which the potential difference across second cell is zero, if:

For full scale deflection of total 50 divisions, 50 mV voltage is required in galvanometer. The resistance of galvanometer if its current sensitivity is 2 div/mA will be:

The colour coding on a carbon resistor is shown in the given figure. The resistance value of the given resistor is:

Five identical cells each of internal resistance $1\Omega$  and emf 5V are connected in series and in parallel with an external resistance 'R'. For what value of 'R', current in series and parallel combination will remain the same?

What equal length of an iron wire and a copper-nickel alloy wire, each of 2mm diameter connected parallel to give an equivalent resistance of 3 $\Omega$ ?

(Given resistivities of iron and copper-nickel alloy wire are $12\mu \Omega$  cm and 51 $\mu \Omega$  cm respectively)

If you are provided a set of resistance 2 $\Omega$ , 4 $\Omega$ , 6 $\Omega$ and 8 $\Omega$ . Connected these resistances so as to obtain an equivalent resistance of $\frac{46}{3}\Omega .$