Chapter 8 Making Use of Electricity

bulb 1 bulb 2 bulb 3

paper stainless steel spoon brass key Which light bulb(s) in the above circuits will light up? (A) (1) and (2) only (B) (1) and (3) only (C) (2) and (3) only (D) (1), (2) and (3)

2. A dry cell is used to light up a light bulb. How does the amount of electrical energy used compare to the amount of light energy produced? The amount of electrical energy used is (A) less than the amount of light energy produced. (B) the same as the amount of light energy produced. (C) more than the amount of light energy produced. sometimes less than and sometimes more than the amount of light energy produced depending on the power rating of the light bulb.

3. The dry cells below has a voltage of 1.5 V. What is the voltage across XY?

X Y (A) 0 V (B) 1.5 V (C) 3.0 V (D) 4.5 V 4. Which of the following circuit diagrams correctly shows a dry cell, a voltmeter and a light bulb connected in parallel? (A) (B)

5. The two voltmeters in the circuit below are identical. The voltage of the dry cell is 1.5 V. Which of the following statements about the circuit is INCORRECT? P

Q (A) If voltmeter Q is disconnected, the reading of voltmeter P will remain unchanged. (B) The reading of voltmeter P is larger than the reading of voltmeter Q. (C) Voltmeters P and Q show the same readings. (D) The reading of voltmeters P and Q will be below 1.5 V if the dry cell is dead. 6. The ammeter in the following circuit shows zero reading. What is the reason?

(A) The bulb is burnt out. (B) The circuit is shorted. (C) The resistance of the fixed resistor is too large. (D) The resistance of the bulb is too small.

7. Which of the following are the correct colours of the wires in an iron?

Live wire Neutral wire Earth wire (A) Blue Brown Green and yellow (B) Green and yellow Blue Brown (C) Brown Blue Green and yellow (D) Brown Green and yellow Blue

8. Q

P The two dry cells in the above circuit are identical and have a voltage of 1.5 V. Also the two voltmeters are identical. Which of the following statements is correct? (A) The reading of voltmeter P is 1.5 V and the reading of voltmeter Q is also 1.5 V. (B) The reading of voltmeter P is 3 V and the reading of voltmeter Q is also 3 V. (C) The reading of voltmeter P is 1.5 V and the reading of voltmeter Q is 3 V. (D) The reading of voltmeter P is 3 V and the reading of voltmeter Q is 1.5 V.

9. The current flowing through a circuit can be varied by (A) a circuit breaker. (B) a fuse. (C) a rheostat. (D) an ammeter.

10. Which of the following diagrams represents a series circuit consisting of a dry cell, two light bulbs and a switch.

(A) (B)

11. The following diagram shows a ring circuit. (A) electrical appliance

(B)

(D) (C)

If the circuit is broken at point A, B, C, or D, at which point will cause the electrical appliance not to work?

12. Which of the following is/are conductors? (1) pencil lead (2) paper (3) glass (A) (1) only (B) (2) only (C) (1) and (3) only (D) (2) and (3) only 13. If we want to measure the voltage across the fixed resistor, where should we connect the voltmeter? (1) (2)

position Q

position P position R (3)

(A) (1) only (B) (2) only (C) (1) and (3) only (D) (2) and (3) only 14. Look at the circuit below. The two bulbs and three ammeters are identical.

If the reading of ammeter A1 is 1 A, then the reading of A2 and A3 are:

Reading of ammeter A2 Reading of ammeter A3 (A) 1A 1 A (B) Greater than 0.5A Less than 0.5 A (C) 0.5 A 0.5 A (D) Less than 0.5 A Greater than 0.5 A 15. Consider the circuit below. The two bulbs are identical.

Three ammeters are used to measure the current at three points on the circuit. If

the reading of ammeter A1 is 3 A, what are the reading of ammeters A2 and A3?

Reading of ammeter A2 Reading of ammeter A3 (A) 1 A 2 A (B) 2 A 1 A (C) 1.5 A 1.5 A (D) 2.5 A 0.5 A

16. What happens to the bulb in the circuit below as the resistance of the rheostat is gradually increased?

(A) The filament of the bulb burns out immediately. (B) The bulb’s brightness decreases. (C) The bulb’s brightness does not change. (D) The bulb’s brightness increases..