Electric Current And Its Effects Class 7 Extra Questions And Answers
In this page we have Worksheet for Class 7 Science Chapter 14: Electric Current and its Effects. We have provided various types of questions for students to practice. Answers to each question is given under the answer tab. First practice the questions on your own and then check the available answers.
Fill in the blanks :
(a) The path along which electric current flows is called an______________________
(b) Current does not flow in an___________________________ electric circuit.
(c) Name the alloy used as the heating element in an electric toaster_________________
(d) A fuse wire has a _____________ electric resistance &________________melting point.
(e) ________________________discovered that electric currents create magnetic field.
(f) The credit for the invention of the electric bulbs goes to__________________________
(g) A combination of two or more cells is called a _________.
(h) Full form of MCB is______________________________________________________
(i) Full form of CFL is_______________________________________________________
Multiple Choice Questions
When a switch is in OFF position,
(i) circuit starting from the positive terminal of the cell stops at the switch.
(ii) circuit is open.
(iii) no current flows through it.
(iv) current flows after some time.
Choose the combination of correct answer from the following.
(a) all are correct
(b) (ii) and (iii) are correct
(c) only (iv) is correct
(d) only (i) and (ii) are correct
Which of the following precautions need not be taken while using electric gadgets/appliances/circuit?
(a) We should never touch a lighted electric bulb connected to the mains.
(b) We should never experiment with the electric supply from the mains or a generator or an inverter.
(c) We should never use just any wire or strip of metal in place of a fuse.
(d) We should never turn the switch in ON position.
Which of the following does NOT contain a heating element?
(a) Electric iron
(b) Electric heater
(c) Electric oven
(d) Electric bell
Which of the following statements is correct of a switch?
(a) It allows the flow of electricity.
(b) It controls the brightness of a bulb.
(c) It controls the power of the batteries.
(d) It fuses a bulb.
Identify the element that is used for making the filament in bulbs.
Answers 2 to 6
Short answer questions
List the factors affecting the amount of heat produced in an element.
Can we use the same fuse in a geyser and a television set? Explain.
What is short-circuiting?
Paheli does not have a night lamp in her room. She covered the bulb of her room with a towel at night to get dim light. Has she taken the right step? Give reason to justify your answer.
Give reason why :-
(a) MCB'S are used in place of fuses in homes & offices nowadays.
(b) We should not touch a lighted electric bulb connected to the mains.
Give reason why :-
(a) CFL's are preferred over electric bulbs.
(b) Copper wire used in household circuits does not get hot, but nichrome wire does.
Long answer questions
What is an electromagnet? Write Down some practical used of Electromagnets.
What is the cause of heating effect of electric current?
How does the magnetic effect of electric current help in the working of an electric bell? Explain and label the given circuit diagram of an Electric bell.
Draw the symbols of the following circuit components.
(i) electric cell
(ii) switch in off position
(iii) electric bulb
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Class 7 Maths
Class 7 Science