Test Paper Of Class 7 Science physics Chapter 14 Electric Current and its Effects
Chapter 14 Test Paper (01)class-7-science-chapter-14-electric-current-And-Its-Effect-01
Class 7 Science Physics Chapter 14 Electric Current and its Effects Test Paper Set-1 Text Form:-
SAMPLE PAPER (01)
CLASS: 7 MAX.MARKS :30
SUBJECT: SCIENCE (Physics) TIME: 1:30 HOUR
CH: 14 (Electric Current and its Effects)
I. All questions are compulsory.
II. This question paper contains 18 questions divided into three Sections:- A, B, and C.
III. Section A has 10 questions of 1 mark each. Section B has 4 questions of 2 mark each and Section C has 4 questions of 3 mark each.
(Section – A)
1. When an electric current flows through a copper wire AB as shown in Figure, the wire
(a) deflects a magnetic needle placed near it.
(b) becomes red hot.
(c) gives electric shock.
(d) behaves like a fuse
2. 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.
3. Which of the following will produce maximum wastage of electricity ?
B. Electric bulb
C. LED lights
D. All are power savers
4. A fuse is connected to the
A. Live wire
B. Neutral wire
C. Earth wire
D. None of these
5. Fuse wire should be placed in the path of _______ wire.
D. None of these
6. In electric fuse, some special wire is used, which is having _______ melting point
A. low B. high
C. moderate D. very high
7. The cable of an electric fan becomes so worn that the live wire makes electrical contact with the metal case The case is earthed The plug to the fan contains a 5 A fuse There is a current of 4 A when the fan works normally What will happen in this case?
A. The current will run to earth and the fuse will not be affected
B. The metal case will become very hot
C. The metal case will become live and dangerous
D. The fuse will melt and switch off the circuit
8. A fuse wire is generally made of
A. tin B. tin-lead alloy
C. copper D. either (a) or (b) above
9. Mark the correct reason why a fuse is always connected in series
A. When fuse melts, it breaks down the entire home circuit and no current flows
B. In series connection the current for the entire house pass through the fuse
10. Fuse wire is made up of
A. Alloy B. Mixture
C. Metals D. Non metals
(Section – B)
11. Name two electric devices for each where
(i) heating effect of current is used and
(ii) magnetic effect of current is
12. Boojho made an electromagnet by winding 50 turns of wire over an iron screw. Paheli also made an electromagnet by winding 100 turns over a similar iron screw. Which electro magnet will attract more pins? Give reason used.
13. When the current is switched on through a wire, a compass needle kept nearby gets deflected from its north-south position. Explain.
14. The bulb in the circuit shown in Fig. does not glow. Can you identify the problem? Make necessary changes in the circuit to make the bulb glow.
(Section – C)
15. Draw the symbols of the following circuit components.
(i) electric cell
(ii) switch in off position
(iii) electric bulb
16. Zubeda made an electric circuit using a cell holder shown in Fig. a switch and a bulb. When she put the switch in the ‘ON’ position, the bulb did not glow. Help Zubeda in identifying the possible defects in the circuit.
17. Boojho made an electromagnet by winding 50 turns of wire over an iron screw. Paheli also made an electromagnet by winding 100 turns over a similar iron screw. Which electromagnet will attract more pins? Give reason.
18. Will the compass needle show deflection when the switch in the circuit shown by Fig. is closed?