Chapter 6: Electrical Circuits & Electric Currents - Science Mcqs for Grade 7 - Set 2

1)   An instrument that gives an accurate measurement of the electric current flowing in a circuit is known as

a. voltmeter
b. galvanometer
c. barometer
d. ammeter
Answer  Explanation 

ANSWER: ammeter

Explanation:
No explanation is available for this question!


2)   A magnet may attract or repel by

a. another magnet
b. electric current
c. resistor
d. dynamo
Answer  Explanation 

ANSWER: another magnet

Explanation:
No explanation is available for this question!


3)   Compared to long thick wire of copper, the short but thick wire would have

a. more resistivity
b. less resistivity
c. equal resistivity
d. may have more or less resistivity
Answer  Explanation 

ANSWER: less resistivity

Explanation:
No explanation is available for this question!


4)   Current can only flow if there is a closed circuit

a. open circuit
b. closed circuit
c. series circuit
d. parallel circuit
Answer  Explanation 

ANSWER: open circuit

Explanation:
No explanation is available for this question!


5)   If someone carrying a knife or gun passes through a detector, it alters the rate of

a. current
b. voltage
c. resistance
d. magnetic field
Answer  Explanation 

ANSWER: magnetic field

Explanation:
No explanation is available for this question!


6)   The electromagnet consists of a coil of wire with

a. steel magnet in it
b. iron magnet in it
c. steel magnet above it
d. iron magnet below it
Answer  Explanation 

ANSWER: iron magnet in it

Explanation:
No explanation is available for this question!


7)   In parallel circuit, the current is

a. equal
b. unequal
c. more powerful
d. less powerful
Answer  Explanation 

ANSWER: unequal

Explanation:
No explanation is available for this question!


8)   In conductors, electrons can flow because their

a. ions are free
b. protons are free
c. electrons are free
d. negative ions are free
Answer  Explanation 

ANSWER: electrons are free

Explanation:
No explanation is available for this question!


9)   Poor conductor of electricity is

a. silver
b. aluminum
c. water
d. copper
Answer  Explanation 

ANSWER: water

Explanation:
No explanation is available for this question!


10)   Earth wire is connected to the

a. ground
b. appliance
c. power house
d. transformer
Answer  Explanation 

ANSWER: ground

Explanation:
No explanation is available for this question!


11)   Another example of 'electromagnets' in trains is

a. bullet train
b. passenger train
c. maglev train
d. cargo train
Answer  Explanation 

ANSWER: maglev train

Explanation:
No explanation is available for this question!


12)   Turning off a switch also put the bulb off, this is because the circuit is

a. cooled down
b. not complete
c. joined
d. unbroken
Answer  Explanation 

ANSWER: not complete

Explanation:
No explanation is available for this question!


13)   'Earphones' are

a. magnets
b. small loudspeakers
c. soft speakers
d. magnetized speakers
Answer  Explanation 

ANSWER: small loudspeakers

Explanation:
No explanation is available for this question!


14)   In 1 minute, 1kW electric fire uses 10 times as much energy as a

a. 1W LED light
b. 10W LED light
c. 100W bulb
d. 0.1W RC Car
Answer  Explanation 

ANSWER: 100W bulb

Explanation:
No explanation is available for this question!


15)   Electrons release energy in the form of

a. heat energy
b. thermal energy
c. sound energy
d. light energy
Answer  Explanation 

ANSWER: thermal energy

Explanation:
No explanation is available for this question!


16)   Some appliances cost more because they need more

a. power
b. space
c. energy
d. electricity
Answer  Explanation 

ANSWER: energy

Explanation:
No explanation is available for this question!


17)   As electrons pass through a bulb, they use

a. energy
b. charge
c. power
d. resistance
Answer  Explanation 

ANSWER: energy

Explanation:
No explanation is available for this question!


18)   Fuses work only

a. in daylight
b. twice
c. once
d. in moonlight
Answer  Explanation 

ANSWER: once

Explanation:
No explanation is available for this question!


19)   When small hammer is attracted by electromagnet, the bell

a. sparks
b. vibrates
c. stops
d. strucks
Answer  Explanation 

ANSWER: strucks

Explanation:
No explanation is available for this question!


20)   William Sturgeon made first electromagnet in

a. 1820
b. 1825
c. 1920
d. 1925
Answer  Explanation 

ANSWER: 1825

Explanation:
No explanation is available for this question!