Ncert- science – class 7- Chapter 10 – Electric Current and Its Effects 1 Welcome to your Ncert- science – class 7- Chapter 10 – Electric Current and Its Effects 1 1. Which of the following is an essential element in an electric circuit ? connecting wires voltmeter switch ammeter None 2. Which of the following is a characteristic of a buzzer? It uses only AC power supply None of the above It has different mechanism from electric bell. It has higher frequency of collision of gong and hammer None 3. A rheostat is used in an electrical circuit to change the potential difference. to change the emf. to change the resistance of the circuit. to change the current through a particular instrument. None 4. The longer line in the symbol of a cell denotes the negative terminal all of these the positive terminal the direction of current None 5. Filament of electric bulb is made up of Low melting point High melting point High boiling point Low boiling point None 6. Which of the following is an advantage of using electrical symbol? It makes the circuit drawing easier. It makes the representation of electrical component easy. It helps in solving the circuits. All of the above. None 7. Which of the following is not a component of electric bell? Ferromagnetic strip None of the above Gong Low magnetic field permanent magnet to attract ferromagnetic strip None 8. Electrons are ___________ particles. Neutral Negatively charged Current Positively charged None 9. When an electric current passes through a solenoid, it acts as a/an bar magnet electric bell insulator resistor None 10. Electric current is said to be pass through a wire when Both electron and neutron pass through it No particle pass through it Only electron passes through it Only proton pass through it None 11. Electromagnet loses its magnetic property when Current is switched OFF Heat is increased Current is very high Current is switched ON None 12. Fuse wire is made up of alloys of High melting point Low melting point Low boiling point High boiling point None 13. Compact fluorescent lamps (CELs) are considered better than ordinary electric bulbs because ? CFLs can be fixed in the ordinary bulb holders . Both CFLs reduce wastage and CFLs can be fixed in the ordinary bulb holders . None of these CFLs reduce wastage None 14. The magnetic effect of the current was discovered by _ ? Oersted Joule Ohm Newton None 15. Electric current is said to be pass through a wire when Only electron passes through it No particle pass through it Only proton pass through it Both electron and neutron pass through it None 16. The strength of the magnetic field due to a solenoid can be increased by by winding solenoid around a plastic rod decreasing the current strength in the solenoid increasing the number of turns in the solenoid all of the above None 17. Which of the following is the best option while considering the safety of household electric appliances ? We should use non-ISI marked MCBs We should use ISI marked MCBs We should use conductors with high melting point in fuses . We should use wire strip as fuses . None 18. Electromagnet is used in Fuse Battery Electric bell Dry cell None 19. Electric current is measured by a device 20. A device which prevents or allows the current to flow through it Conductor Motor Terminal Switch None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
