Class 7 Science Chapter 10 Practice Question Answers - Electric Current and Its effects

Q1. Bulbs, wires, cells and switches are known as the of a circuit.
(a) element
(b) switch
(c) filament
(d) none of these
Ans: (a)
Wires, cells, switches, bulbs are element of a circuit.

Q2. An element measure the flowing an electric current is:
(a) voltmeter
(b) filament
(c) circuit
(d) ammetet
Ans: (d)
An ammeter measure the flowing electric current.

Q3. An element measure the potential difference between two points in an electric circuit is:
(a) voltmeter
(b) filament
(c) circuit
(d) ammeter
Ans: (a)
Voltmeter measure the difference of two points.

Q4. Electric current has energy called:
(a) voltmeter
(b) filament
(c) electrical energy
(d) none of these
Ans: (c)
Electric current has electric energy.

Q5. The magnetic material around the coil is wound is called:
(a) magnetic substance
(b) core
(c) soft iron
(d) none
Ans: (b)
The magnetic material around the coil is wound is core.

Q6. Very strong electromagnets are used for lifting:
(a) fans
(b) washing machines
(c) heavy iron pieces
(d) none of these
Ans: (c)
Very strong electromagnet is used for lifting iron pieces.

Q7. A safety device that cuts off the current in a circuit if a sudden heavy current starts flowing in it is:
(a) fuse
(b) ammeter
(c) solenoid
(d) none of these
Ans: (a)
Fuse is a safety device that cuts off the current.

Q8. A cylindrical coil of current carrying wire is:
(a) voltmeter
(b) ammeter
(c) fuse
(d) solenoid
Ans: (d)
A solenoid is a cylindrical coil of wire.

Q9. A coil of insulated currrent- carrying wire wound around a piece of a magnetic substance is:
(a) voltmeter
(b) magnetic coil
(c) electromagnet
(d) none of these
Ans: (c) electromagnet
An electromagnet is a coil of insulated wire.

Q10. Which of these is not circuit element ?
(a) potential difference
(b) voltmeter
(c) resistor
(d) battery
Ans: (c)
Resistor is not a circuit element.

Q11. Which of these appliances does not use on electro magnet?
(a) washing
(b) refrigerator
(c) room heater
(d) electric bell
Ans: (c)
Room heater does not use an electro magnet.

Q12. The fuse wire:
(a) never breaks
(b) breaks on shorting of wire
(c) breaks on flowing of excessive current
(d) both (b) and (c)
Ans: (d)
Always fuse breaks on shorting of wire and flowing exessive current.

Q13. Which of the following liquid is bad conductor of electricity:
(a) salted water
(b) orange juice
(c) lemon juice
(d) none of these
Ans: (d)
None of these Liquid is bad conductor of electricity.

Q14. Which of the following substance is conductor of electricity:
(a) rubber
(b) paper
(c) nails
(d) plastic
Ans: (c)
Nails is conductor of electricity.

Q15. The electric current which is broken at some point is called:
(a) open circuit
(b) closed circuit
(c) short circuit
(d) long circuit
Ans: (a)
Open circuit is broken at some point.

Q16.  symbol represents:
(a) cell
(b) battery
(c) closed circuit
(d) open key
Ans: (c)
 This symbol represents closed key.

Q17. A circuit diagram represent on:
(a) switch
(b) electrical circuit
(c) cells
(d) none of these
Ans: (a)
A circuit diagram represent on electrical circuit.

Q18. A control consisting of a electrical device for making or breaking or changing the connections in a circuit is:
(a) a switch
(b) a key
(c) both (a) and (b)
(d) none of these
Ans: (c)
Both (a) and (b) are control consisting device of electricsl.

Q19.   symbol represents: 
(a) electric bulb
(b) electric cell
(c) battery
(d) wire
Ans: (b)
Electrical cell represents symbol.

Q20.   symbol represents:
(a) wire
(b) battery
(c) cell
(d) switch in ‘ON’ position
Ans: (d)
 symbol represents switch in ‘ON’ position.

Q21.  symbol represents:
(a) wire
(b) cell
(c) bulb
(d) battery
Ans: (a)
 symbol represents wire.

Q22. Such a combination of two or more cells is called :
(a) wire
(b) cell
(c) bulb
(d) battery
Ans: (d)
Combination of two or more cells is called battery.

Q23. The batteries used in tractors, trucks and inverter are also made from:
(a) cells
(b) wire
(c) battery
(d) none of these
Ans: (a)
The batteries used in tractors, trucks are also made from cells.

Q24. The positive terminal of one cell is connected to the:
(a) positive terminal
(b) negative terminal
(c) wire
(d) bulb
Ans: (b)
The positive terminal of one cell is connected to the negative terminal.

Q25. The bulb glows as soon as the switch is moved to the:
(a) ‘ON’ position
(b) ‘OFF’ position
(c) both (a) and (b)
(d) none of these
Ans: (a)
The bulb glows as soon as the switch is ‘ON’ position.

Q26. The electric current flows from the end of cell marked ‘+’ called the:
(a) negative terminal
(b) positive terminal
(c) electric current
(d) none of these
Ans: (d)
The cell marked ‘+’ is called positive terminal.

Q27. Through the metal wires to the end marked ‘ — ’ called the:
(a) bulb
(b) positive terminal
(c) battery
(d) negative terminal
Ans: (d)
The marked ‘ is called the negative terminal.

Q28. The bulb has a thin wire called:
(a) battery
(b) cell
(c) filament
(d) none of these
Ans: (b)
The bulb has thin wire called filament.

Q29. A fan used electric current to rotate to blow:
(a) air
(b) current
(c) wire
(d) none of these
Ans: (a)
A fan uses electric current to rotate to blow air.