Page 1 - X-CBW-ELECTRICITY

SAI INTERNATIONAL SCHOOL, BHUBANESWAR

COMPETENCY BASED WORKSHEET
CLASS X
CHAPTER – ELECTRICITY
SL NO QUESTIONS MARKS
For question 1 To 3 two statements are given. One labelled Assertion (A) and the other
labelled Reason(R). Select the correct answer to these questions from the codes (a), (b),
(c) and (d) as given below:
(a) Both A and R are true and R is the correct explanation of the assertion.
(b) Both A and R are true, but R is not the correct explanation of the assertion.
(c) A is true, but R is false.
(d) A is false, but R is true.
(e) A and R are false.
1. Assertion (A): One circuit with 15 A current rating is used for appliances 1
such as geysers and air coolers.
Reason (R): Appliances with metallic body are connected to an earth wire
with low resistance.
2. Assertion (A): Alloys are commonly used in electrical heating devices like 1
electric iron and heater.
Reason(R): Resistivity of an alloy is generally higher than that of its
constituent metals but the alloys have low melting points than their
constituent metals.
3. Assertion: At high temperatures, metal wires have a greater chance of short 1
circuiting.
Reason: Both resistance and resistivity of a material vary with temperature.
4. The graph below shows the variation of resistivity of copper with 1
temperature.

Kishore constructs a simple circuit as shown below. The resistor is made of
copper.

He then heats the copper resistor. What will happen to the current flowing
through the circuit? Why?
A. The current will increase because the resistance of copper increases with
an increase in temperature