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