Science : Ch 12 – Electricity

The instrument used for measuring electric current is:

A boy records that 4000 joule of work is required to transfer 10 coulomb of charge between two points of a resistor of 50 Ω. The current passing through it is:

To get 2 Ω resistance using only 6 Ω resistors, the number of them required is

Two devices are connected between two points say A and B in parallel. The physical quantity that will remain the same between the two points is

The least resistance obtained by using 2 Ω, 4 Ω, 1 Ω and 100 Ω is:

Two resistors are connected in series gives an equivalent resistance of 10 Ω. When connected in parallel, gives 2.4 Ω. Then the individual resistance are

The resistance of hot filament of the bulb is about 10 times the cold resistance. What will be the resistance of 100 W-220 V lamp, when not in use?

A cooler of 1500 W, 200 volt and a fan of 500 W, 200 volt are to be used from a household supply. The rating of fuse to be used is:

Insulators consists of:

The formula which states the relation between potential diference, current and resistance

The ammeter is always connected in series because

At the time of short circuit, the electric current in the circuit

The equivalent resistance of a series combination of two resistances is X Ohm. If the resistance are of 10 Ohm and 40 Ohm respectively, the value of X will be:

An ideal ammeter is one which has

The instrument used for measuring electric current is