MEASUREMENT/UNIT

1. In the following which is fundamental physical quantity? [66th B.P.S.C (RE EXAM)2020]

(a) Force
(b) Velocity
(c) Electric current
(d) work

Correct Answer: (c) Electric current

Solution:There are seven fundamental physical quantities (which are measured in base or fundamental units):

2. The unit of power is - [U.P.S.C(GIC)2010]

(a) Volts
(b) Hertz
(c) Watt
(d) Neutron

Correct Answer: (c) Watt

Solution:

In the physics, power is the rate of doing work or of transferring heat or electrical energy i.e the amount of energy transferred or converted per unit time.
Power(p)=work(w)/Time(t)
The SI unit of power is watt, which is equal to joule per second.
Power is always represented in watt(W) or Kilowatt(KW)

3. The unit of electrical power is : [65th B.P.S.C. (Pre) 2019,64th B.P.S.C.(Pre) 2018]

(a) Ampere
(b) Volt
(c) Coulamb
(d) Watt

Correct Answer: (d) Watt

Solution:Electrical power is the rate of work per unit time ,at which electrical energy is transferred by an electrical circuit. The SI unit of electrical power is watt. Ampere is the unit of electric current, volt is the unit of electric potential and coulomb is the unit of electric charge in the SI system.

4. The unit of force is - [M.P.P.S.C (Pre)1990]

(a) Faraday
(b) Fermi
(c) Newton
(d) Rutherford

Correct Answer: (c) Newton

Solution:The SI unit of is Newton or kg.m/sec²
Force =mass × acceleration
In physics, something that cause a change in the state of object ( motion or rest) is called force. The modern definition of force (an object's mass multiplied by its acceleration ) was given by Issac Newton in his laws of motion.

5. The unit of work : [U.P.S.C. (Pre) 1996]

(a) Joule
(b) Neutron
(c) Dyne
(d) Watt

Correct Answer: (a) Joule

Solution:

When a force acts to move a object, then work done by the force is equivalent to the product of force and displacement in the direction of force .
It is scalar quantity.
The SI unit of work is Newton meter, which is also called as joule.
Joule is also the unit of energy.

6. Frequency is measured in : [64th B.P.S.C. (Pre)2018]

(a) hertz
(b) meter/second
(c) radian
(d) watt

Correct Answer: (a) hertz

Solution:The hertz is the (symbol :Hz) is the derived unit of frequency in the international system of units ( SI system) and is defined as one cycle per second.

7. What is the measured in hertz ? [65th B.P.S.C. (Pre)2019 ]

(a) Frequency
(b) Heat
(c) Energy
(d) Quality

Correct Answer: (a) Frequency

Solution:The hertz is the (symbol :Hz) is the derived unit of frequency in the international system of units ( SI system) and is defined as one cycle per second.

8. The SI unit of electrical resistivity of the conductor is - [M.P.P.S.C(Pre)1993]

(a) Volts
(b) Faraday
(c) Ampere
(d) Ohm-meter

Correct Answer: (d) Ohm-meter

Solution:The SI unit of electrical resistivity is ohm-meter(Ωm).It is commonly represented by the-
Greek word ρ(rho) defined as ρ=RA/L
Where R= Resistance of material
l=length of the material
A=Cross section of the material
ρ=resistivity as per option.

9. Ohm-meter is the SI unit of : [66th B.P.S.C.(Pre) (Re.exam) 2020]

(a) Resistance
(b) Conductance
(c) Resistivity
(d) Charge

Correct Answer: (c) Resistivity

10. Which of the following pair is not correctly matched? [U.P.P.C.S (Pre)2022]

Quantity	SI Unit
power of lens	Diopter
Pressure	Pascal
Activity of radio-active substance	Curie
Heat	Joule

Correct Answer: (c)

Solution:Unit of radioactivity is defined as the activity of a quantity of radioactive material where one decay takes place per second.The SI unit of the radioactivity is Becquerel (Bq) and this term is named after Henri Becquerel .