Sunday, April 26, 2015

CBSE Class 8 Science - CH 14 - Chemical Effects of Electric Current (MCQs)

Chemical Effects of Electric Current

MCQs
CBSE Class 8 Science - CH 14 - Chemical Effects of Electric Current (MCQs)

Q1: The liquid will conduct electric current in a circuit when the vessel is filled with _________.

(a) distilled water
(b) salt solution
(c) air
(d) helium


Q2: Which of the following substance is not a good conductor of electricity?

(a) copper
(b) aluminium
(c) rubber
(d) mercury


Q3: The decomposition of liquid compound on passing an electric current though it is known as ______

(a) electroplating
(b) electrolysis
(c) magnetic effect
(d) electro-resistivity


Q4: The glowing of filament bulb is due to


(a) heating effect of electric current
(b) physical effect of electric current
(c) magnetic effect of electric current
(d) chemical effect of electric current


Q5: In a LED, the longer lead/leg is connected to ____________

(a) positive terminal of the battery
(b) negative terminal of the battery
(c) either positive of negative terminal of the battery
(d) none of these


Q6: Most liquids that conduct electricity are solutions of ____________

(a) acids
(b) bases
(c) salts
(d) all of these


Q7: Name the chemist who showed bubbles of oxygen and hydrogen are produced when electric current passes through water.

(a) William Nicholson
(b) William Harvey
(c) Luigi Galvani
(d) Alessandro Volta


Q8: Pure water is a good conductor of electricity. The statement is

(a) always true.
(b) false
(c) sometimes true.
(d) none of these


Q9: To prevent iron from corrosion it is electroplated with __________

(a) aluminium
(b) copper
(c) oxygen
(d) zinc


Q10: The whole apparatus of electrodes, electrolytes and vessel containing them is called _____

(a) thermometer
(b) electrometer
(c) voltameter
(d) ammeter


Answer:
1: (b) salt solution
2: (c) rubber
3: (b) electrolysis
4: (a) heating effect of electric current
5: (a) positive terminal of the battery
6: (d) all of these [note the word solutions]
7: (a) William Nicholson
8: (b) false
9: (d) zinc
10:(c) voltameter

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