Chapter 6: Electrical Circuits & Electric Currents - Science Mcqs for Grade 7 - Set 5

1)   The 12V car battery would

a. kill you
b. electrocute you
c. give you a nasty shock
d. cause your body burst
Answer  Explanation 

ANSWER: give you a nasty shock

Explanation:
No explanation is available for this question!


2)   If a live wire touches the metal casing of an object, the metal casing becomes

a. neutral
b. earthed
c. live
d. hot
Answer  Explanation 

ANSWER: live

Explanation:
No explanation is available for this question!


3)   The electrolyzed substance is known as

a. conductor
b. insulator
c. electrolyte
d. electro decay
Answer  Explanation 

ANSWER: electrolyte

Explanation:
No explanation is available for this question!


4)   Filament is present in

a. center of the sealed glass
b. front of the sealed glass
c. roots of the sealed glass
d. head of the sealed glass
Answer  Explanation 

ANSWER: center of the sealed glass

Explanation:
No explanation is available for this question!


5)   The vibration of cone produces

a. light
b. sound
c. heat
d. crystals
Answer  Explanation 

ANSWER: sound

Explanation:
No explanation is available for this question!


6)   Radio, TV, CD Player and sound system have

a. loudspeakers
b. microphones
c. antennas
d. cathode tubes
Answer  Explanation 

ANSWER: loudspeakers

Explanation:
No explanation is available for this question!


7)   A part of an electric circuit which is used to limit the amount of electric current flowing through the circuit is known as

a. diode
b. thermistor
c. radiator
d. resistor
Answer  Explanation 

ANSWER: diode

Explanation:
No explanation is available for this question!


8)   The slowing down of electrons depends upon

a. material
b. mass of conductor
c. volume of conductor
d. length of conductor
Answer  Explanation 

ANSWER: material

Explanation:
No explanation is available for this question!


9)   When water is electrolyzed, the gas collected at cathode, is

a. sulphur
b. oxygen
c. hydrogen
d. sulphur dioxide
Answer  Explanation 

ANSWER: hydrogen

Explanation:
No explanation is available for this question!


10)   For protection of electrical appliances

a. resistors can be used
b. fuses can be used
c. thick wires can be used
d. thin wires can be used
Answer  Explanation 

ANSWER: fuses can be used

Explanation:
No explanation is available for this question!


11)   The resistors that have set resistance, are known as

a. fixed resistors
b. variable resistors
c. thermistors
d. fixators
Answer  Explanation 

ANSWER: fixed resistors

Explanation:
No explanation is available for this question!


12)   If temperature rises very high, it can be used in

a. electric lamps
b. electric heaters
c. electric coolers
d. electric fans
Answer  Explanation 

ANSWER: electric lamps

Explanation:
No explanation is available for this question!


13)   The first thing on which the amount of consumed energy depends, is

a. amount of ions in a wire
b. amount of resistance
c. amount of electron's flow
d. length of time, the appliance has been used for
Answer  Explanation 

ANSWER: length of time, the appliance has been used for

Explanation:
No explanation is available for this question!


14)   An example in which light emitting diodes are used, is

a. calculator
b. hard drive
c. optical drive
d. analog watch
Answer  Explanation 

ANSWER: calculator

Explanation:
No explanation is available for this question!


15)   Against resistance when electric current is forced through a conductor, electrons collide with the atoms of conductor which make them

a. hot
b. cold
c. vibrate
d. tremble
Answer  Explanation 

ANSWER: vibrate

Explanation:
No explanation is available for this question!


16)   The energy which is used to push electrons towards the positive terminal is known as

a. mechanical energy
b. kinetic energy
c. electrical energy
d. potential energy
Answer  Explanation 

ANSWER: electrical energy

Explanation:
No explanation is available for this question!


17)   A simple enclosed length of wire that has a low melting point is known as

a. resistor
b. fuse
c. circuit breaker
d. thermistor
Answer  Explanation 

ANSWER: fuse

Explanation:
No explanation is available for this question!


18)   Current conducting path through wires, bulb and battery is known as

a. conductor
b. circuit
c. electrical flow
d. convectional flow
Answer  Explanation 

ANSWER: circuit

Explanation:
No explanation is available for this question!


19)   The relationship between magnetism and electricity was discovered in

a. 1818
b. 1819
c. 1820
d. 1821
Answer  Explanation 

ANSWER: 1819

Explanation:
No explanation is available for this question!


20)   The positive electrode of the electrolytic cell is known as

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

ANSWER: anode

Explanation:
No explanation is available for this question!