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