February 19, 2026February 19, 2026 Quiz on Electric current and its Effect Welcome to your Class 7 Electric Effects and Current A bulb connected to a circuit does not glow even though wires and bulb are intact. What is the most logical cause? Circuit is open Resistance is zero Bulb is too bright None Cells connected in series produce more brightness in a bulb because they: Decrease current Increase voltage Increase resistance None Which material would be most suitable for making a heating element? Nichrome Copper Aluminium None Why do connecting wires in a circuit not glow like bulb filaments? They have no current They have no electrons They have low resistance None A fuse wire melts when current exceeds limit. This happens because fuse wire has: Zero resistance Low melting point High melting point None If live and neutral wires touch directly, the current becomes very large. This condition is called: Insulation Short circuit Overloading None A compass needle placed near a current-carrying wire deflects. This demonstrates: Chemical effect Heating effect Magnetic effect None Why does reversing current direction reverse compass deflection? Magnetic field direction changes Wire thickness changes Resistance changes None Which factor will increase the strength of an electromagnet? Increasing current Removing iron core Reducing number of turns None An electromagnet is preferred over permanent magnet in cranes because it: Is lighter Is stronger always Can be switched off None Which statement correctly compares conductors and insulators? Insulators allow easy flow Conductors allow current easily Conductors oppose current strongly None Increasing resistance in a wire while keeping current same will: Decrease heat produced Stop heat production Increase heat produced None Why is tungsten used in bulb filaments? High melting point No resistance Low melting point None Overloading in a circuit occurs when: Wire length is small Too few appliances are connected Too many appliances draw current None If a circuit is closed but no source is present, current will: Not Flow Flow only in wires Flow slowly None Which property of a wire mainly determines its resistance? Shape only Length and thickness Colour None Which change will make a bulb glow brighter? Increasing number of cells in series Increasing wire resistance Decreasing voltage None Why is rubber used to cover electric wires? It increases voltage It is an insulator It conducts current None A solenoid behaves like a magnet because: It stores electricity It has iron ends Current in coil produces magnetic field None What happens when switch is OFF in a circuit? Circuit becomes open Resistance becomes zero Voltage increases None Which device works mainly on heating effect of current? Electric motor Electric iron Compass None If resistance of a wire decreases, heat produced will: Remain same Increase Decrease None Why is an iron core placed inside a coil to make an electromagnet? To increase magnetic strength To decrease resistance To reduce current None Which condition is necessary for current to flow? Long wire only Closed path Thick wire only None A bulb glows dimly instead of brightly. This indicates: Higher current Lower current Zero resistance None MCB is preferred over fuse because MCB: Conducts more current Cannot break circuit Can be reset None Which situation produces maximum heat in a wire? High current and high resistance Low current and low resistance No current None Why does a short circuit produce sparks? Resistance becomes very low Voltage disappears Current becomes very small None If number of turns in coil is doubled, electromagnet strength will: Increase Decrease Remain Same None Which statement best explains why electrical appliances have different thickness wires inside? To look different To control resistance and heating To change color None 1 out of 6 Name Email Time's up Electric current and its effect free pdf notes Useful Links: CBSE CLASS 6 SOCIAL SCIENCE CBSE CLASS 6 SCIENCE CBSE CLASS 7 SOCIAL STUDIES CBSE CLASS 7 MATHS CBSE CLASS 8 MATHS CBSE CLASS 8 SCIENCE CBSE CLASS 10 MATHS CBSE CLASS 10 SCIENCE
