Science 1 Marks Question

No.

The given circuit does not have any current source. In the absence of current, the wire does not behave as a magnet and hence, the compass needle will not show any deflection.

The scientist who discovered the magnetic effect of electric current is Hans Christian Oersted.

True.
An electric bell has a piece of iron wound by a coil. When current passes through this coil, it behaves as an electromagnet.

When current is switched ‘on’ in a room heater, it produces heat.
Working of a room heater is based on the phenomenon of heating effect of electric current.

Fuse wire is used to prevent sudden excess flow of current. Cell provide current of fix magnitude So fuse wire are not used in circuit containing electric cell.

Electric Bell, Motor, Fan etc.

An electric fuse is a safety device to prevent damage to an electrical circuit when excessive current flows through it.

The region around the magnet, where force of attraction or repulsion can be felt by magnetic materials, is called as magnetic field.

Some of the electric appliances where the heating effect of the electric current is used are electric heater, geyser, micro-oven, room heater, boiler, etc.

1. West to East.
2. East to West.

If two magnetic lines of force will intersect each other then, at the point of intersection there will be two different directions of magnetic field which is not possible.

Magnitude of electric current, perpendicular distance between that point and conductor.

Compact Fluorescent Lamps.

Electric fuse.

A fuse is thus a safety device which prevents damages to electrical circuits and possible fires.

The safety device based on the heating effect of electric current is called a fuse.
Fuse is a safety device, which limits current in circuit and breaks the circuit if the current exceeds its maximum limit.

For a bulb to glow, it must be connected to a battery because a bulb will require more power. The battery is the source of electric current in a circuit which glows the bulb. Hence, the battery is essential in a circuit.

Electric Current is the flow of electrons. But an electric Circuit is the closed path in which electric current flows.

True.
The wire of the fuse is made of special material which has a low melting point.
When large current passes through a fuse, it melts quickly and breaks the circuit.

An electric cell produces electricity from the Chemicals stored in it.
Chemicals stored, an electric cell is a device capable of changing chemical energy into electrical energy (electricity).

None of the bulb will glow when the switch is in the 'off' position as there will be no electric current in the circuit.

The heat produced in a wire depends on the current flowing in the wire and the resistance of the wire.

Electric Circuit The closed path in which electric current flows.

A good fuse wire is made of tin as it has a low melting point.

Gives electric shock.
It deflects a magnetic needle placed near it because a magnetic field is created when the current passes through it.

Length and thickness of the wire, the duration of flow of current, and the material of the wire.

No, the bulb does not glow when the circuit is opened. The bulb glows only when the circuit is closed.

By using magnetic compass which, shows deflection.

Electric fuse is required in all electrical appliances to prevent damage from excessive current flow and during short circuit.

Fuse is always connected with live wire.

The fuse rating is the maximum current that the fuse can carry without melting.

A combination of two or more cells connected together is called a battery. It is formed by connecting the positive terminal of one cell to the negative terminal of another.

Multiple Circuit Breakers.

False.
working of an electromagnet is based on the magnetic effect of electric current.
An electromagnet behaves as a magnet when current passes through it. Hence, it will attract a piece of iron.

The process, due to which a changing magnetic field in a conductor induces a current in another conductor, is called electromagnetic induction.

An electromagnet is a coil of wire wound on a soft iron core which acts as a magnet due to the magnetic field of electric current.

If cells are placed side by side, then with the help of some connecting wires, the positive terminal of one cell is connected to the negative terminal of other to produce a combined power of all cells which can be called a battery.

The devices that work on the basis of magnetic effects of current are loudspeaker and electric bell.

In an electrical Circuit when we replace electrical components with their symbols we call it Circuit diagram.

When the current is passed through the wire wound on the nail, it behave as electromagnet. Due to this reason, the nails attract the pins.

An electromagnet cannot be used for separating plastic bags from a garbage heap as it attracts only iron pieces and will not attract plastic bags.

Heating effect of electric current and magnetic effect of electric current.

Electric fan and electrical motor are the electrical appliances in which electromagnets are used.

By inserting the steel bar inside the solenoid and switching on electric current.

Induced magnetic field will be in the form of concentric circles in the plane of paper.

Air is not filled in electric bulbs because on lighting, the filament of the bulb becomes hot and this heat will result in burning in presence of air.

A compartment that holds two or more cells together to form a battery is called a cell holder.

When electric current flows through a conductor, a part of electrical energy get converted into heat energy due resistance offered to electron.

The working of electric generator is based on the principle of electromagnetic induction. The Important parts of electric generator are armature, slip rings, brushes and field magnets.

A closed path formed by the interconnection of electrical components through which electric current flows is called an electrical circuit.

If the filament of the bulb is broken, the circuit will not be complete. So, the bulb will not glow.

It is overloaded by connecting too many devices to it. When too many devices get connected, then a circuit is said to be overloaded.

Longer line in the symbol for cell representsits positive terminal.

These switches turn off automatically when there is an overload or a short circuit.

The electric room heater, electric roti maker, electric iron, toaster, hair dryer, electric stove, immersion water heater, food warmer, electric coffee maker, electric rice cooker and geyser.

The combination of two or more cells is called a battery.
To make a battery, the negative terminal of one cell is connected to the positive terminal of the next cell and so on.

Our body is a good conductor of electricity.
Conductor Our body is a good conductor of electricity as it allows the electric current to pass through it.

There is a minimum limit on the current which can safely flow in the electric circuits.
In case of electric fuse, there is only a maximum limit on the current which can safely flow in the electric circuits.

The field lines inside the solenoid are parallel straight lines. This indicates that the magnetic field is uniform and is therefore, same at all points inside it.

When the current through the coil stops flowing, the coil does not remain an electromagnet.

The value of the current in a circuit increases heavily at the time of short circuit.

A combination of two or more cells is called a Battery.
Battery A combination of two or more cells, where the positive terminal of one cell is connected to the negative terminal of the next cell, is called a battery.

In an electric circuit a fuse is a Safety device to prevent possible fire.
Safety device If by accident the current exceeds the safe limit, in a circuit, the fuse will blow off and break the circuit and will prevent damage to circuit and possible fire.

The field lines outside the solenoid are curved lines. This indicates that the magnetic field is non-uniform.

The lighted bulb connected to main supply should not be touched by our hand directly, as a lighted bulb can be very hot and can burn our hand as well.

False.
To make a battery of two cells, the negative terminal of one cell must be connected to the positive terminal of the other cell.

It becomes red hot and gives out heat.