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Q1. When the switch is in ON condition, the circuit is :

• incomplete, open and current flows through it
• incomplete, closed and current flows through it
• complete, open and current flows through it
• complete, closed and current flows through it

Solution

When the switch is in ON condition, the circuit is complete, closed and current flows through it.

Q2. Circuit Breaker Device which can be used in place of fuse in domestic electric wiring is called :

• CDB
• DCB
• MCD
• MCB

Solution

Circuit Breaker Device which can be used in place of fuse in domestic electric wiring is called MCB.

Q3. In the symbol of the electric cell, the longer line represents the _____________.

• positive terminal
• negative terminal
• zero-potential terminal
• neutral-potential terminal

Solution

In the symbol of the electric cell, the longer line represents the positive terminal.

Q4. A battery is a group of:

• only three cells
• only two cells
• two or more cells
• none of the above

Solution

A battery is a group of two or more cells combined together.

Q5. Switch in a circuit is placed:

• At left side of the battery
• At right side of the battery
• Near the negative terminal of the cell/battery
• Anywhere in the circuit

Solution

Switch in a circuit can be placed anywhere in the circuit.

Q6. When current flows in the coil rounded around an iron core then the iron core becomes an:

• electromagnet
• permanent magnet
• ordinary magnet
• bar magnet

Solution

When current flows in the coil rounded around an iron core then the iron core becomes an electromagnet.

Q7. What material of the core should be used for making a strong electromagnet?

• Brass
• Copper
• Steel
• Soft iron

Solution

Soft iron core should be used for making a strong electromagnet.

Q8. When an electric current flows through a wire :

• The wire gets heated.
• A magnetic field is produced around the wire. Both (1) & (2)
• Both (1) & (2)
• None of the above

Solution

When an electric current flows through a wire, the wire gets heated ( heating effect of current) and a magnetic field is produced around it ( magnetic effect of current).

Q9. The coil of wire in an electric heater used for cooking is called __________.

• Filament
• Element
• High tension wire
• Electric wire

Solution

The coil of wire in an electric heater used for cooking is called element.

Q10. Full form of MCB is :

• Mega Circuit Breaker
• Miniature Control Breaker
• Miniature Circuit Breaker
• Miniature Circuit Bond

Solution

MCB stands for Miniature Circuit Breaker.

Q11. Nichrome wire is used in

• CFL
• electric fuse
• hair dryer
• MCB

Solution

The heating element in most hair dryers is a bare, coiled nichrome wire that's wrapped around insulating mica boards.

Q12. An electric bulb is used for light but it also gives heat. This is not desirable. This results in the wastage of electricity. This wastage can be reduced by using :

• Heaters
• Coolers
• Light emitting diodes (LEDs)
• Compact fluorescent lamps

Solution

Compact fluorescent lamps (CFLs) reduce wastage of electricity and can be fixed in the ordinary bulb holders.

Q13. The magnetic field produced due to the current passing through a conductor is proportional to the ______.

• Length of conductor
• Conducting material
• Electric current
• Diameter of conductor

Solution

The magnetic field produced due to the current passing through a conductor is proportional to the electric current.

Q14. At the time of short circuit, the current in the circuit :

• reduces substantially
• does not change
• increases heavily
• varies continuously

Solution

At the time of short circuit, the current in the circuit increases heavily.

Q15. A wire gets hot when an electric current passes through it. This is :

• Peltier effect of electric current
• Magnetic effect of electric current
• Chemical effect of electric current
• Heating effect of electric current

Solution

A wire gets hot when an electric current passes through it. This is heating effect of electric current.

Q16. A soft iron bar is introduced inside a current carrying coil. The magnetic field inside the coil:

• Will become zero
• Will increase
• Will remain unaffected
• Will decrease

Solution

A soft iron bar is introduced inside a current carrying coil. The magnetic field inside the coil will increase.

Q17. A current carrying coil of an insulated wire wrapped around a piece of iron is called _____________.

• Permanent magnet
• Temporary magnet
• Bar magnet
• Electromagnet

Solution

A current carrying coil of an insulated wire wrapped around a piece of iron is called an electromagnet.

Q18. The filament of an electric bulb is made of a thin wire of:

• copper
• aluminium
• nichrome
• tungsten

Solution

The filament of an electric bulb is made of a thin wire of tungsten.

Q19. When electric current passes through a wire, the magnetic needle kept near it shows deflection from its north-south position. This is :

• Peltier effect of electric current
• Magnetic effect of electric current
• Seeman effect of electric current
• Heating effect of electric current

Solution

When electric current passes through a wire, the magnetic needle kept near it shows deflection from its north-south position. This is magnetic effect of electric current.

Q20. An electric circuit is said to be ______ when the switch is in ON position.

• closed and complete
• open and complete
• closed and incomplete
• none of the above

Solution

An electric circuit is said to be closed and complete when the switch is in ON position.

Q21. A fire may be caused when :

• the fuse melts.
• excess current passes through the circuit.
• the switch is on
• switch of MCB falls

Solution

There is a maximum limit on the current which can safely flow through a circuit. If by accident the current exceeds this safe limit, the wires may become overheated and may cause fire.

Q22. A switch is a device that is :

• used to allow current to flow in the circuit
• used to cut off  the flow of current
• used to allow current to flow in an appliance
• used to allow current to flow in the circuit or in an electrical appliance and to cut it off when desired.

Solution

A switch is a device that is used to allow current to flow in the circuit or in an electrical appliance and to cut it off when desired.

Q23. The electromagnets are also used to separate which kind of material from the junk?

• Electric material
• Magnetic material
• Plastic material
• Glass material

Solution

The electromagnets are also used to separate magnetic material from the junk.

Q24. Fuse wire has a _________ melting point and is made of alloy of ________ and _________. If the current in the circuit rises too high, the fuse wires ________.

• High, lead, aluminium , melt
• High, lead, tin, melt
• Low, lead, aluminium, melt
• Low, lead, tin, melt

Solution

Fuse wire has a low melting point and is made of alloy of lead and tin. If the current in the circuit rises too high, the fuse wires melt.

Q25. Which of the following does not use electromagnets?

• Loudspeaker
• Voltmeter
• Mixer grinder
• Gas oven

Solution

Gas oven does not use electromagnets.

Q26. When electric current passes through the filament of a bulb, it gives off: A. Sound B. Heat C. Magnetism D. Light

• A and D
• A and B
• B and C
• B and D

Solution

When electric current passes through the filament of a bulb, it gives off heat and light.

Q27. Electromagnets are based on the :

• Chemical effect of electric current
• Heating effect of electric current
• Magnetic effect of electric current
• Kinetic effect of electric current

Solution

Electromagnets are based on the magnetic effect of current.

Q28. Which of the following is true regarding the formation of a battery?

• The positive terminal of one cell is connected to the negative terminal of the next cell.
• The positive terminal of one cell is connected to the positive terminal of the next cell.
• The negative terminal of one cell is connected to the negative terminal of the next cell.
• None of the above

Solution

In a battery, the positive terminal of one cell is connected to the negative terminal of the next cell.

Q29. An electric bulb works on the principle of :

• Chemical effect of electric current
• Heating effect of electric current
• Magnetic effect of electric current
• Electronic effect of electric current

Solution

An electric bulb works on the principle of heating effect of electric current.

Q30. Most of the fuses operate due to

• Heating effect of current
• Magnetic effect of current
• Electrostatic effect of current
• None of the above

Solution

Fuses work on heating effect of electric current.

Q31. In an electric bell :

• Electrical energy is converted into magnetic energy.
• Electrical energy is converted into sound energy.
• Magnetic energy is converted into sound energy.
• Sound energy is converted into electrical energy.

Solution

In an electric bell electrical energy is converted into sound energy.

Q32. Which of the following materials is preferred for making heating element?

• Copper
•  Nichrome
• Aluminium
• Tungsten

Solution

Nichrome is used as a material for heating element because it has a high melting point.

Q33. Which of the following acts as the electromagnet in an electric bell?

• Iron strip
• Coil
• Hammer
• Screw

Solution

Coil acts as the electromagnet in an electric bell.

Q34. We often use a simple setup, known as ________, to demonstrate and use the magnetic effects of currents in the laboratory.

• Metre rod
• Solenoid
• Fuse
• None of the above

Solution

We often use a simple setup, known as solenoid, to demonstrate and use the magnetic effects of currents in the laboratory.

Q35. A fuse should have :

• low melting point and high resistance
• low melting point and low resistance
• high melting point and high resistance
• high melting point and low resistance

Solution

A fuse should have low melting point and high resistance.

Q36. Who was the first person to notice the magnetic effect of electric current?

• Faraday
• Ampere
• Oersted
• Volta

Solution

Hans Christian Oersted was the first person to notice the deflection of compass needle every time the current was passed through the wire kept near it.

Q37. When the direction of current flowing through a coil is reversed, the direction of deflection in the needle compass kept near it ___________.

• remains unaffected
• gets reversed
• points north-south
• points east-west

Solution

When the direction of current flowing through a coil is reversed, the direction of deflection in the needle compass kept near it also gets reversed.

Q38. The direction of magnetic field lines is taken as:

• North to South
• South to North
• Entering both poles
• Leaving both poles

Solution

The direction of magnetic field lines is taken as North to South.

Q39. The amount of heat produced in a wire depends on its :

• Material
• Length
• Thickness
• All the above

Solution

The amount of heat produced in a wire depends on its material, length and thickness.

Q40. When the switch is in the 'OFF' position :

• the circuit is incomplete
• the circuit is open
• no current flows through the circuit
• all the above