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: Heating effect of electric current Magnetic effect of electric current Lighting effect of electric current Chemical effect of electric current None 2. 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 3. Electromagnets are made up of: steel Soft iron aluminum copper None 4. A fuse is used in an electrical appliance : To protect the appliance and its cable To earth the appliance To change the current rating of the applicance To change the efficiency of the applicance None 5. Which one of the following heater element is used in electric press Lead wire Copper wire Nichrome wire Iron wire None 6. When the switch of an electric bell is on then electric current in it : Flows continuously First flows in one direction and after sometime in other direction Flows and stops in succession Flows in beginning and then stops forever None 7. What must happen for an electromagnet to have a magnetic field? It must be connected to an electrical source. It must be heated. It must be touching another magnet. It must be lined up with earth's magnetic field None 8. An electric bell works on the .......... effect of a current and uses an .......... Heating, Electromagnet Magnetic, Permanent magnet Magnetic, Electromagnet Heating, Permanent magnet None 9. The essential requirements for a good heating element are _________________. Low resistivity and low melting point Low resistivity and high melting point High resistivity and low melting point High resistivity and high melting point None 10. The components required to make a simple series circuit to light a bulb are Both Cell, switch and Bulb, wires Wires and cell Bulb and wires Cell and switch None 11. What happens to a circuit when the switch is off? There is a gap in the circuit The circuit is complete Electricity flows continuously Electricity flows discontinuously 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.
