# Measuring Mass

## Trending Questions

**Q.**If the size of a nucleus is 10thpower of -15meters is scales up to the tip of a sharp pin is 10thpower of -5meters , then what roughly is the size of the atom?

**Q.**The number of particle crossing per unit area perpendicular to Z axis per unit time is given by N=-D(N2-N1)/(Z2-Z1), where N2 and N1 are the number of particle per unit volume at Z2 and Z1 respectively. What is the dimensional formula for D?

**Q.**A particle of mass m and charge q moves with a constant velocity v along the positive x direction. It enters a region containing a uniform magnetic field B directed along the negative z direction, extending from x = a to x = b. The minimum value of v required so that the particle can just enter the region x > b is

- qb B/m
- q(b−a)B/m
- qaB/m
- q(b+a)B/2m

**Q.**A semi circular wire of radius R is rotated with angular velocity ω about an axis passing through one end and perpendicular to the plane of wire in a uniform magnetic field of magnitude Bo. q is midpoint of the semicircle, then the ratio of potential difference between p and r to q and r is (i.e Vpr:Vqr)

- √2:1
- 1:2
- √3:√2
- 2 :1

**Q.**

A hollow spherical body of inner and outer radii 6 cm and 8 cm respectively floats half-submerged in water. Find the density of the material of the sphere.

**Q.**15.Radius of He nucleus is 3 fermi. The radius of 16 S 32 nucleus will be

**Q.**A long straight wire carries a certain current and produces a magnetic field 2 ×10−4 Wb m−2 at a perpendicular distance of 5 cm from the wire. A particle say 'c' having charge equal to that of an electron is situated at 5 cm from the wire moves with a velocity of 107 m/s towards the wire perpendicularly. The magnitude of force experienced by the particle will be (charge of an electron =−1.6×10−19 C )

- 3.2 N
- 3.2×10−16 N
- 1.6×10−16 N
- 0 N

**Q.**

If mass of earth is M, radius is R and gravitational constant is G, then work done to take 1 kg mass from earth surface to infinity will be

**Q.**A particle having specific charge s starts from rest in a region where the electric field has constant direction but magnitude verifying with time t as E=E0t. In time t, it is observed that the particle acquires a velocity v after covering a distance x, then

- x=12(E0s)t3
- x=16(E0s)t3
- v=(E0s)t2
- v=125(E0s)t2

**Q.**

If $36.4\xc3\u2014{10}^{-15}$ g of mass is transferred when fur is rubbed with silk, find the number of electrons lost by fur? (mass of electron $=9.1\xc3\u2014{10}^{-31}$ kg).

**Q.**

Device used to measure mass of chemicals is ___________.

**Q.**A proton is accelerating in a cyclotron. It comes out of the cyclotron with the kinetic energy K. If it is required to have kinetic energy 4K, then the radius of the circular path will be _____ times of its initial value.

- 1
- 2
- 3
- 4

**Q.**

What force will produce a moment of force$4.5N-m$, if the perpendicular distance between the force and the turning point is$20cm$?

**Q.**How does a thread (placed over on ice cube with a weight of 2 -2 kg on both sides ) passes through the ice cube and does not leaves any cuts on it?

**Q.**

Complete the following sentences:

The mass of a proton is ________ times that of an electron.

**Q.**

Brief description of dimensional analysis.

**Q.**The diagram shows a cuboid block made from a metal of density 2.5g/cm3

What is the mass of the block?

- 8.0kg
- 16kg
- 50g
- 100g

**Q.**Two spherical bodies of mass M and 5M and radii R and 2R released in free space with initial separation between their centres equal to 12R. If they attract each other due to gravitational force only, then the distance covered by the smaller body before collision is

- 4.5 R
- 7.5 R
- 1.5 R
- 2.5 R

**Q.**The mass of an oxygen atom is 16.00 u. Find its mass in kg.

**Q.**One molecule of water (H2O) contains two atoms of hydrogen and one atom of oxygen. A hydrogen atom has a mass of 1.0 u and an atom of oxygen has a mass of 16 u, approximately.

How many molecules of water are in the world's oceans, which have an estimated total mass of 1.4×1021 kg?

**Q.**Water is poured into a container that has a small leak. The mass m of the water is given as a function of time t by m=5.00 t0.8−3.00t+20.00, with t≥0, m in grams, and t in seconds.

In kilograms per minute, what is the rate of mass change at t=2.00 s

**Q.**15.Radius of He nucleus is 3 fermi. The radius of 16 S 32 nucleus will be

**Q.**A block of iron has dimensions 2m×0.5m×0.25m. The density of iron is 7.8gcm−3 Find the mass of block.

**Q.**Two particles of mass m1 and m2 are approaching towards each other under their mutual gravitational field. If the speed of the particle is v, the speed of the center of mass of the system is equal to:

- (m1−m2)vm1+m2
- m2m1v
- m1m2v
- zero

**Q.**Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describe circular paths of radii R1and R2, respectively. The ratio of the masses of X to that of Y is

- (R1/R2)2
- R1/R2
- (R1/R2)1/2
- R2/R1

**Q.**Using conversions and data in the chapter. determine the number of hydrogen atoms required to obtain 1.0 kg of hydrogen. A hydrogen atom has a mass of 1.0 u.

**Q.**How are the units of weight: kgf and newton related?

**Q.**What is the mass of 5m3 of cement of density 3000 kg/m3

**Q.**Which quantity : Mass or weight, does not change of place?

**Q.**Which of the following is the best estimate for the mass of all the people living on the Earth?

- 2∗108kg
- 1∗109kg
- 3∗1011kg
- 2∗1010kg
- 4∗1012kg