Ncert- science – class 7- Chapter 10 – Electric Current and Its Effects 2 Welcome to your Ncert- science – class 7- Chapter 10 – Electric Current and Its Effects 2 1. When electric current passes through the filaments of a bulb, it starts emitting light due to: Lighting effect of electric current Magnetic effect of electric current Heating effect of electric current Chemical effect of electric current None 2. A fuse is used in an electrical appliance : To change the current rating of the applicance To protect the appliance and its cable To earth the appliance To change the efficiency of the applicance None 3. The components required to make a simple series circuit to light a bulb are Cell and switch Both Cell, switch and Bulb, wires Bulb and wires Wires and cell None 4. Which pair is not correct for the instruments used in the laboratory and their uses from the following? Resistor - To supply the electric energy to circuit Ammeter - To measure the electric current Voltmeter - To measure the electric potential differene Galvanometer - To detect the presence of current None 5. What must happen for an electromagnet to have a magnetic field? It must be connected to an electrical source. It must be lined up with earth's magnetic field It must be touching another magnet. It must be heated. None 6. Electromagnets are made up of: Soft iron aluminum steel copper None 7. What happens to a circuit when the switch is off? Electricity flows discontinuously Electricity flows continuously There is a gap in the circuit The circuit is complete None 8. An electric bell works on the .......... effect of a current and uses an .......... Heating, Electromagnet Magnetic, Electromagnet Heating, Permanent magnet Magnetic, Permanent magnet None 9. Which one of the following heater element is used in electric press Lead wire Iron wire Copper wire Nichrome wire None 10. When the switch of an electric bell is on then electric current in it : Flows in beginning and then stops forever First flows in one direction and after sometime in other direction Flows and stops in succession Flows continuously None 11. The essential requirements for a good heating element are _________________. High resistivity and low melting point Low resistivity and low melting point Low resistivity and high melting point High resistivity and high melting point 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.
