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