Free Physical Quantities and Units MCQs with Answers

• A. 5nJ -> 5 mJ -> 5 kJ -> 5 MJ
• B. 5 nJ -> 5 kJ -> 5 MJ -> 5 mJ
• C. 5 kJ -> 5 mJ -> 5 MJ -> 5 nJ
• D. 5 mJ -> 5 nJ -> 5 kJ -> 5 MJ

Explanation: In order to solve this you must know the value and symbol of the number prefix. (Refer to the table below)5 kJ = 5 x10^3J5 mJ = 5 x10^-3 J5 MJ = 5 x10^6 J5 nJ = 5 x10^-9 JThe order of increasing magnitude will be 5 x10^-9 J < 5 x10^-3 J < 5 x10^3J < 5 x 10^6 J5 nJ < 5 mJ < 5 kJ < 5 MJ

• A. Green cadmium light
• B. Violet cadmium light
• C. Red cadmium light
• D. Blue cadmium light

Explanation: Michelson measured the length of the standard meter using the interference fringes produced by red cadmium light. He used a device called an interferometer to measure the wavelength of the light and used it to determine the length of the standard meter.The interferometer creates interference patterns by splitting a beam of light into two paths, allowing them to recombine and create an interference pattern. By measuring the fringe pattern and knowing the wavelength of the light source, the length of the standard meter can be determined.

• A. 104 ergs
• B. 105 ergs
• C. 106 ergs
• D. 107 ergs

Explanation: One Joule is the amount of work done when a force of 1 newton displaces a mass through a distance of 1 meter in the direction of the force applied. One joule = Nm (SI ) One joule = 107 ergs (CGS) Hence, D is the correct option

• A. Distance travelled by earth in one year
• B. Distance travelled by star in one year
• C. Distance travelled by light in one year
• D. Distance travelled by light in one galactic year

Explanation: The following is the solution:Option C is correct since it gives the right definition of one light year.Option A is incorrect since it gives simply the distance of earth in orbit.Option B is incorrect since it gives simply the distance travelled by the star in space.Option D is incorrect since one galactic year is equal to 230 million light-years. The galactic year, also known as a cosmic year, is the duration of time required for the Sun to orbit once around the centre of the Milky Way Galaxy.

• A. (Amperes)2ohm
• B. Joules/ sec
• C. Amperes x volts
• D. Amperes/volt

Explanation: Power is measured in watts. P = I x V (power is current times voltage) and it is NOT current divided by voltage. So, A/V can't be equivalent to watt and hence, option D is correct.

• A. Kg ms-2
• B. Kgm2s-2
• C. Kgm2s-3
• D. None of these

Explanation: According to Newton's 2nd lawF=maWhere F is force , m is mass and a is acceleration . The unit of mass is 'kg' and the unit of acceleration is 'm/s2' .The units of F will be,F=kgm/s2F=kgms-2

• A. Giga
• B. Tera
• C. Mega
• D. Deca

Explanation: The correct answer is Tera, as it represents 1012, the largest power of ten among the options. Giga represents 109, Mega represents 106, and Deca represents 101. Therefore, Tera is the highest power multiple here.

• A. Ampere
• B. Volt
• C. Coulomb
• D. Calorie

Explanation: The correct answer is Coulomb, which is the SI unit used to measure electric charge. The other options are units for different physical quantities: Ampere for electric current, Volt for electrical potential difference, and Calorie for energy.

• A. Am
• B. Js-1
• C. As
• D. C

Explanation: In terms of SI base units, 1 C is the equivalent of 1 ampere-second, which can be expressed as 1 C = 1 A ⋅ 1 s (or C = A ⋅ s). This can also be thought of as an ampere being equal to 1 coulomb divided by 1 s, as in 1 A = 1 C / 1 s (or A = C / s). In other words, if the current in a circuit is 1 A, 1 C of charge passes through a point in the circuit every second

• A. Base Quantities
• B. Physical Quantities
• C. Derived Quantities
• D. Supplementary Quantities

Explanation: Physical Quantities, by definition, are quantities that can be measured with the help of an instrument to give a numerical value with a unit representing the quantity itself.