Test Paper Of Class 7 Science Physics Chapter 14 Electric Current and its Effects
Chapter 14 Test Paper (02)class-7-science-chapter-14-electric-current-And-Its-Effect-02
Class 7 Science Physics Chapter 14 Electric Current and its Effects Test Paper Set-1 Text Form:-
SAMPLE PAPER (02)
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. Choose the statement which is not correct in the case of an electric fuse.
(a) Fuses are inserted in electric circuits of all buildings.
(b) There is a maximum limit on the current which can safely flow through the electric circuits.
(c) There is a minimum limit on the current which can safely flow in the electric circuits. (d) If a proper fuse is inserted in a circuit it will blow off if current exceeds the safe limit.
2. Three bulbs A, B, C are connected in a circuit as shown in Figure When the switch is ‘ON’
(a) bulb C will glow first.
(b) bulb B and C will glow simultaneously and bulb A will glow after some time.
(c) all the bulbs A,B and C will glow at the same time.
(d) the bulbs will glow in the order A, B and C.
3. 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 the 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
4. Why CFL is better in comparison to bulb ?
A. Because bulb produce heat which results in wastage of electricity and CFL saves electricity.
B. Because bulb produce heat which results in production of more electricity than CFL
C. Because CFLs size is bigger than bulb
D. Because CFL produce heat which results in saving of electricity.
5. Which of the following is/are energy efficient products?
A. Tube lights
6. A filament of low melting point metal/alloy is used in-
A. Electric bulb
C. Electric iron
D. Room heater
7. In an electric circuit, a fuse is connected :
A. in the live wire
B. in the neutral wire
C. in the earth wire
D. Any of these
8. Fuse is always connected to the ______ wire.
A. live B. neutral
C. earth D. green
9. An electric iron draws a current of 15 A from a 220 V supply. What is the cost of using iron for 30 min every day for 15 days if the cost of unit (1 unit == 1 k W hr) is 2 rupees?
A. Rs. 49.5 B. Rs. 60
C. Rs. 40 D. Rs. 10
10. Electric Fuse wire is working on ___________ principle.
A. control of voltage in circuit
B. chemical effect of electric current
C. control of current in circuit
D. heating effect of electric current
(Section – B)
11. In Fig. shows four cells fixed on a board. Draw lines to indicate how you will connect their terminals with wires to make a battery of four cells.
12. Name any two effects of electric current.
13. Can we use the same fuse in a geyser and a television set? Explain.
14. Why do we cover plug pin holes which are within the reach of children with cello tape or a plastic cover when not in use?
(Section – C)
15. Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness. Both of them connected the wires as shown in the circuit given in Figure, The current flowing in both the circuits is the same.
(i) Will the heat produced in both the cases be equal? Explain.
(ii) Will the heat produced be the same if the wires taken by them are of equal lengths but of different thickness? Explain.
16. How does the magnetic effect of electric current help in the working of an electric bell? Explain with the help of a diagram.
17. An electrician is carrying out some repairs in your house. He wants to replace a fuse by a piece of wire. Would you agree? Give reasons for your response.
18. In the circuit shown in Fig.
(i) Would any of the bulb glow when the switch is in the ‘OFF’
(ii) What will be the order in which the bulbs A, B and C will glow
when the switch is moved to the ‘ON’ position?