One Mark Questions Answers

PHYSICS

MEASUREMENT

TEXT BOOK EXERCISES

I. Choose the correct answer:

1. Choose the correct one.

(a) mm < cm < m < km

(b) mm > cm > m > km

(c) km < m < cm < mm

(d) mm > m > cm > km

[Answer: (a) mm < cm < m < km]

2. Rulers, measuring tapes and metre scales are used to measure

(a) mass

(b) weight

(c) time

(d) length

[Answer: (d) length]

3. 1 metric ton is equal to

(a) 100 quintals

(b) 10 quintals

(c) 1/10 quintals

(d) 1/100 quintals

[Answer: (b) 10 quintals]

4. Which among the following is not a device to measure mass?

(a) Spring balance

(b) Beam balance

(c) Physical balance

(d) Digital balance

[Answer: (a) Spring balance] 

II. Fill in the blanks :

1. Metre is the unit of length _.

2. 1 kg of rice is weighed by beam balance.

3. Thickness of a cricket ball is measured by vernier caliper.

4. Radius of a thin wire is measured by screw gauge.

5. A physical balance measures small differences in mass up to 1 mg or less.

III. State whether true or false. If false, correct the statement :

1. The SI unit of electric current is kilogram.

Answer: False.

Correct statement: The SI unit of electric current is ampere.

2. Kilometre is one of the SI units of measurement.

Answer: True.

3. In everyday life, we use the term weight instead of mass.

Answer: True.

4. A physical balance is more sensitive than a beam balance.

Answer: True.

5. One Celsius degree is an interval of 1 K and zero degree Celsius is 273.15 K.

Answer: True.

6. With the help of vernier caliper we can have an accuracy of 0.1 mm and with screw gauge we can have an accuracy of 0.01 mm.

Answer: True.

IV. Match the following :

1.

Length - kelvin

Mass - metre

Time - kilogram

Temperature - second

Answer:

Length - metre

Mass - kilogram

Time - second

Temperature - kelvin

2.

Screw gauge - Vegetables

Vernier caliper - Coins

Beam balance - Gold ornaments

Digital balance - Cricket ball

Answer:

Screw gauge - Coins

Vernier caliper - Cricket ball

Beam balance - Vegetables

Digital balance - Gold ornaments

V. Assertion and reason type questions :

Mark the correct answer as :

(a) Both A and R are true but R is not the correct reason.

(b) Both A and R are true and R is the correct reason.

(c) A is true but R is false.

(d) A is false but R is true

1. Assertion (A) : The scientifically correct expression is “The mass of the bag is 10 kg”

Reason (R) : In everyday life, we use the term weight instead of mass.

(a) Both A and R are true but R is not the correct reason.

(b) Both A and R are true and R is the correct reason.

(c) A is true but R is false.

(d) A is false but R is true

[Answer: (a) Both A and R are true but R is not the correct reason.]

2. Assertion (A) : 0°C = 273.16 K. For our convenience we take it as 273 K after rounding off the decimal.

Reason (R) : To convert a temperature on the Celsius scale we have to add 273 to the given temperature.

(a) Both A and R are true but R is not the correct reason.

(b) Both A and R are true and R is the correct reason.

(c) A is true but R is false.

(d) A is false but R is true

[Answer: (b) Both A and R are true and R is the correct reason.]

3. Assertion (A) : Distance between two celestial bodies is measured in terms of light year.

Reason (R) : The distance travelled by the light in one year is one light year.

(a) Both A and R are true but R is not the correct reason.

(b) Both A and R are true and R is the correct reason.

(c) A is true but R is false.

(d) A is false but R is true

[Answer: (d) A is false but R is true]

Assertion: Distance between two celestial bodies is measured in terms of astronomical unit.