An iron ball at 40°C is dropped in a mug containing water at 40°C. The heat will

1

(a)

flow from iron ball to water

(b)

not flow from iron ball to water or from water to iron ball

(c)

flow from water to iron ball

(d)

increase the temperature of both

Stainless steel pans are usually provided with copper bottoms. The reason for this could be that

1

(a)

copper bottom makes the pan more durable

(b)

such pans appear colourful

(c)

copper is a better conductor of heat than the stainless steel

(d)

copper is easier to clean than the stainless steel

A marble tile would feel cold as compared to a wooden tile on a winter morning because the marble tile

1

(a)

is a better conductor of heat than the wooden tile

(b)

is polished while wooden tile is not polished

(c)

reflects more heat than wooden tile

(d)

is a poor conductor of heat than the wooden tile

Heat is a form of:

1

(a)

Energy

(b)

Light

(c)

Electricity

(d)

Work

Cooking utensils are made of metals because they are:

1

(a)

Durable

(b)

Malleable

(c)

Good conductors of heat

(d)

Do not break on heating

Temperature is the measure of _____ of an object.

1

(a)

hotness

In coastal areas, cold air flows in the day from sea to land. It is called ______

1

(a)

sea breeze

When we come out in the sun, we feel ______

1

(a)

warm

All hot bodies radiate _______

1

(a)

heat

The three modes of heat transfer are radiation ________ and conduction.

1

(a)

convection

Our sense of touch about hotness or coldness is not always reliable

1

(a) False

(b) True

Normal temperature of human body is 98.6°C.

1

(a) True

(b) False

In all cases, heat flows from a hotter object to a colder object.

1

(a) False

(b) True

Water at higher temperature feels more hot.

1

(a) False

(b) True

Marking on clinical thermometer is from 0⁰C to 100⁰C.

1

(a) True

(b) False

Which metal is used in the bulb of thermometer?

1

(a)

Mercury (Hg).

What is the SI unit of temperature.

1

(a)

Kelvin.

Name the three modes of transfer of heat.

1

(a)

Conduction, convection and radiation.

Which is the bad conductor of heat?

1

(a)

Wood is a bad conductor of heat.

Do all liquids expand on heating?

1

(a)

All liquids expand on heating except water which contracts when heated below 4°C.

In a mercury thermometer, the level of mercury rises when its bulb comes in contact with a hot object. What is the reason for this rise in the level of mercury?

2

(a)

Shopkeepers selling ice blocks usually cover them with jute sacks. Explain why.

2

(a)

Why convection is not possible in solids?

2

(a)

What are insulators?

2

(a)

Why ice is wrapped in gunny bags?

2

(a)

Give two examples each of conductors and insulators of heat.

1.5

(a)

Differentiate between two modes of transfer of heat, i.e. convection and conduction.

3

(a)

Instead of water explain the reason, why do the mercury is used in the thermometer?

3

(a)

What precautions are needed while reading a laboratory thermometer?

3

(a)

On last Monday, Pankaj was dealing immense cough and cold. Besides this, he was suffering from a great headache. So, he decided to take a leave on that day so that he could take some rest at his home. After one hour he thought to check his fever through a clinical thermometer, so before using it, he washed it and started shaking it very fastly in his hand, so that the mercury level of thermometer gets reduced. At the same time, his elder brother Vishwas scold him and suggested him to shake thet hermometer slowly.
(a) State some precautionary measures while checking the fever through a clinical thermometer.
(b) Mention the values showed by the elder brother of Pankaj ( i.e. Vishwas).

3

(a)

Explain the sea breeze and land breeze.

1.5

(a)