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

1)   Electroplating is used to coat less expensive metals with

a. gold
b. silver
c. platinum
d. valuable metals
Answer  Explanation 

ANSWER: valuable metals

Explanation:
No explanation is available for this question!


2)   Semiconductors are also found in

a. light emitting diodes
b. liquid crystal displays
c. cathode ray tubes
d. cathode ray oscilloscopes
Answer  Explanation 

ANSWER: light emitting diodes

Explanation:
No explanation is available for this question!


3)   Adding more bulbs to a circuit with one battery would

a. make them brighter
b. make them sharper
c. make them dimmer
d. make them colorless
Answer  Explanation 

ANSWER: make them dimmer

Explanation:
No explanation is available for this question!


4)   Nichrome (mixture of nickel and chromium) resists

a. less electricity than copper
b. less electricity than aluminum
c. more electricity than copper
d. more electricity than aluminum
Answer  Explanation 

ANSWER: more electricity than copper

Explanation:
No explanation is available for this question!


5)   In parallel circuits, the voltage is

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

ANSWER: equal

Explanation:
No explanation is available for this question!


6)   Friction can cause transfer of

a. neutrons
b. protons
c. electrons
d. photons
Answer  Explanation 

ANSWER: electrons

Explanation:
No explanation is available for this question!


7)   A doorbell and electric bell use

a. magnets
b. current
c. electromagnets
d. resistors
Answer  Explanation 

ANSWER: electromagnets

Explanation:
No explanation is available for this question!


8)   The negative electrode of the electrolytic cell is known as

a. Cathode
b. Anode
c. Posit rode
d. Nematode
Answer  Explanation 

ANSWER: Cathode

Explanation:
No explanation is available for this question!


9)   Overloading in power sockets can cause them to

a. spark
b. burst
c. catch fire
d. burn
Answer  Explanation 

ANSWER: catch fire

Explanation:
No explanation is available for this question!


10)   If a hair drier uses a current of 2A but we fit 1A fuse in it. The fuse will

a. glow
b. burst
c. melt
d. remain safe
Answer  Explanation 

ANSWER: melt

Explanation:
No explanation is available for this question!


11)   On track magnetic levitation trains

a. clip
b. float
c. ride
d. skid
Answer  Explanation 

ANSWER: float

Explanation:
No explanation is available for this question!


12)   The electrons move from

a. positive to negative terminal
b. negative to positive terminal
c. both a and b
d. positive to positive terminal
Answer  Explanation 

ANSWER: negative to positive terminal

Explanation:
No explanation is available for this question!


13)   Materials that are insulators when cold and conductors when hot are known as

a. semi insulators
b. semi conductors
c. semi electrolytes
d. electrolytes
Answer  Explanation 

ANSWER: semi conductors

Explanation:
No explanation is available for this question!


14)   Materials that do not allow electrons to flow through them are known as

a. insulators
b. conductors
c. electrolytes
d. bases
Answer  Explanation 

ANSWER: insulators

Explanation:
No explanation is available for this question!


15)   Short circuit occurs when the current takes up

a. more voltage
b. less voltage
c. short path
d. long path
Answer  Explanation 

ANSWER: short path

Explanation:
No explanation is available for this question!


16)   To prevent overload and overheating of wires

a. fuses are used
b. circuit breakers are used
c. fuses and circuit breakers are used
d. fuses and resistor are used
Answer  Explanation 

ANSWER: fuses and circuit breakers are used

Explanation:
No explanation is available for this question!


17)   The magnetic field of the coil and the permanent magnet

a. attract each other
b. repel each other
c. combine with each other
d. stay with each other
Answer  Explanation 

ANSWER: repel each other

Explanation:
No explanation is available for this question!


18)   ELCB is an abbreviation of

a. electrolytic circuit breaker
b. earth locking circuit breaker
c. earth leakage circuit breaker
d. electric leakage circuit breaker
Answer  Explanation 

ANSWER: earth leakage circuit breaker

Explanation:
No explanation is available for this question!


19)   Electricity is required to

a. light up homes
b. clean your car
c. flush the toilet
d. change weather
Answer  Explanation 

ANSWER: light up homes

Explanation:
No explanation is available for this question!


20)   A block of impure copper is used as

a. cathode
b. anode
c. posit rode
d. nematode
Answer  Explanation 

ANSWER: anode

Explanation:
No explanation is available for this question!