Class 7 Science MCQ Electric Current and Its Effects

Question : A glowing filament will be

(a) At a low temperature
(b) At a high temperature
(c) At atmospheric temperature
(d) At the temperature of ice

Question : In a bulb there is a thin wire called

(a) filament
(b) coil
(c) element
(d) fuse wire

Question : An electromagnet is one which behaves as a magnet when current is ______

(a) Allowed to flow through
(b) Not allowed to flowthrough
(c) Stopped from flowing through it

Question : When the current flowing through the fuse wire exceeds the safety limit, then it will be ______ breaking the circuit.

(a) Melted away
(b) Remains the same
(c) Damages the circuit
(d) Makes the circuit remain connecte(d)

Question : Who discovered that when a compass needle is kept nearer to an electric circuit in which current is flowing ,it deflects.

(a) Hans Christian Oersted
(b) Michael Faraday
(c) Galileo
(d) Newton

Question : When electric current passes through a wire , it behaves like a magnet. This is the

(a) Magnetic effect of current
(b) Electrical effect of current
(c) Heating effect of current
(d) Optical effect of current

Question : An electromagnet is one which behaves as a magnet when current is __

(a) Allowed to flow through
(b) Not allowed to flowthrough
(c) Stopped from flowing through it
(d) None of Above

Question : A glowing bulb becomes warm due to the

(a) heating effect of current
(b) magnetic effect of current
(c) chemical effect of current
(d) physical effect of current

Question : A glowing filament will be

(a) At a low temperature
(b) At a high temperature
(c) At atmospheric temperature
(d) At the temperature of ice

Question : The heat energy produced by a glowing bulb can be minimised by using _____ bulbs in place of ordinary electric bulbs __________________________.

(a) A candle
(b) CFL bulbs
(c) Torch
(d) Kerosene lamp

Question : The wire which melts and breaks the circuit when large current is allowed to flow through it is called

(a) A fuse wire
(b) Electric wire
(c) Connecting wire
(d) Filament

Question : _________piece is attracted by an electromagnet

(a) Wood
(b) Iron
(c) Plastic
(d) Rubber

Question : Electric Bell works on the principle

(a) Electrical energy is converted into mechanical energy
(b) Electrical energy is converted into sound energy
(c) Mechanical energy is converted into sound energy
(d) Sound energy is converted into electrical energy.

Question : Choose the statement which is not correct in the case of an electric fuse.

(a) Fuses are inserted in electric circuits of all buildings.
(b) There is a maximum limit on the current which can safely flow through the electric circuits.
(c) There is a minimum limit on the current which can safely flow in the electric circuits.
(d) If a proper fuse is inserted in a circuit it will blow off if current exceeds the safe limit.

Question : When electric current flows through a conductor, the conductor becomes

(a) liquid
(b) vapor
(c) hot
(d) cold

Question : An electric iron is an example of

(a) heating effect of current
(b) magnetic effect of current
(c) chemical effect of current
(d) physical effect of current

Question : Nichrome is used a coil of heater because

(a) It has high resistance and high melting point
(b) Low resistance and high melting point
(c) High resistance and low melting point
(d) None of the above

Question : A combination of two or more cells is called __________________________.

(a) A Battery
(b) A Button cell
(c) An Electric cell
(d) Truck Battery

Question : When an electric circuit from the positive terminal of the battery to the negative terminal of the battery is complete, then the circuit is said to be

(a) Closed
(b) OPen
(c) No change
(d) Disconnected

Question : Current flows through the circuit when the circuit is in the ________condition. __________________________.

(a) Closed
(b) Open
(c) Broken
(d) Incomplete

Question : An electric wire connected in a circuit gets heated up when current is allowed to flow through it . This is due to

(a) Heating effect of current
(b) Electrical effect of current
(c) Musical effect of current
(d) Optical effect of current

Question : In making a battery

(a) positive terminal of one cell is connected to the negative terminal of the next cell
(b) positive terminal of one cell is connected to the positive terminal of the next cell
(c) negative terminal of one cell is connected to the negative terminal of the next cell
(d) none of the above

Question : When Electric Current Is Passed Through The Filament Of A Bulb, It Gives Off:

(a) Sound and heat
(b) Heat and magnetism
(C) Heat and light
(d) Light

Question : Fuse wire is generally made of

(a) tin and lead
(b) nickel and chromium
(c) nickel and copper
(d) chromium and silver

Question : Start To Your Left Side, Three Bulbs A, B, C Are Connected In A Circuit With The Help Of Wire, Switch And Three Cells. There Are No Defected Pieces Of Anything. If Switch Is ON Position:

(a) Bulb C will glow first.
(b) Bulb B and C will glow simultaneously and bulb A will glow after sometime.
(C) All the bulbs A, B and C will glow at the same time.
(d) The bulbs will glow in order A, B and C.

Question : Why are symbols used for electronic components?

(a) It makes it easier to draw the circuit diagrams
(b) It is essential to draw the circuit diagrams
(c) It helps to show the direction of flow of current in a circuit
(d) All of the above

Question : The Compact Fluorescent Electric Lamp Has:

(a) Nichrome filament
(b) Chromium filament
(C) Tungsten filament
(d) No filament

Question : In A Filament Type Bulb, A Lot Of Electric Energy Is Wasted In The Form Of:

(a) Magnetism
(b) Sound
(C) Light
(d) Heat

Question : Which of the following materials is a conductor?

(a) Silver
(b) Rubber
(c) Cloth
(d) Plastic

Question : At The Time Of Short Circuit, The Current In The Circuit:

(a) Reduce substantially
(b) Does not change
(C) Increase heavily
(d) Varies continuously

Question : The metal which is poor conductor of electricity is

(a) Gold
(b) Iron
(c) Aluminium
(d) Mercury

Question : The coil of wire contained in an electric heater is known as

(a) component
(b) element
(c) circuit
(d) spring

Question : Electromagnet loses its magnetic property when

(a) Current is very high
(b) Current is switched OFF
(c) Heat is increased
(d) Current is switched ON