MCQ 1011 Mark
A soap bubble in vacuum has a radius of $3 \mathrm{~cm}$ and another soap bubble in vacuum has a radius of $4 \mathrm{~cm}$. If the two bubbles coalesce under isothermal condition, then the radius of the new bubble is
- A
$2.3 \mathrm{~cm}$
- B
$4.5 \mathrm{~cm}$
- ✓
$5 \mathrm{~cm}$
- D
$7 \mathrm{~cm}$
AnswerCorrect option: C. $5 \mathrm{~cm}$
(c) $r=\sqrt{r_1^2+r_2^2}=\sqrt{9+16}=5 \mathrm{~cm}$
View full question & answer→MCQ 1021 Mark
A car of mass ' $m$ ' is driven with acceleration ' $a$ ' along a straight level road against a constant external resistive force ' $R$. When the velocity of the car is ' $V$, the rate at which the engine of the car is doing work will be
- A
$R V$
- B
$\mathrm{maV}$
- ✓
$(R+m a) V$
- D
$(m a-R) V$
AnswerCorrect option: C. $(R+m a) V$
Force required to move with constant velocity
$\therefore$ Power $=F V$ Forceisrequired to oppose the resistive force $R$ and also to accelerate the body of mass with acceleration$a$).
$\therefore$ Power $=(R+m a) V$
View full question & answer→MCQ 1031 Mark
A particle of mass $m$ moving with velocity $v$ strikes a stationary particle of mass $2 \mathrm{~m}$ and sticks to it. The speed of the system will be
- A
$v / 2$
- B
$2 \mathrm{v}$
- ✓
$v / 3$
- D
$3 v$
AnswerCorrect option: C. $v / 3$
View full question & answer→MCQ 1041 Mark
At which of the following temperatures, the value of surface tension of water is minimum
- A
$4 \mathrm{C}$
- B
$25 . \mathrm{C}$
- C
$50 \cdot \mathrm{C}$
- ✓
$75 . \mathrm{C}$
AnswerCorrect option: D. $75 . \mathrm{C}$
$75 . \mathrm{C}$
View full question & answer→MCQ 1051 Mark
A frictionless track $A B C D E$ ends in a circular loop of radius $R$. A body slides down the track from point $A$ which is at $a$ height $h=5$ $\mathrm{cm}$. Maximum value of $R$ for the body to successfully complete the loop is
AnswerCorrect option: D. $2 \mathrm{~cm}$
From the conservation of energy,
$mgh =\frac{1}{2} mv ^2 $
$v =\sqrt{2 gh }$
The condition for completing the loop is given as,
$\sqrt{2 g h}=\sqrt{5 g R} $
$R=\frac{2 \times 5}{5} $
$=2\ cm$
Thus, the maximum value of $R$ for the body to successfully complete the loop is $2\ cm .$
View full question & answer→MCQ 1061 Mark
Two soap bubbles have different radii but their surface tension is the same. Mark the correct statement
- ✓
Internal pressure of the smaller bubble is higher than the internal pressure of the larger bubble
- B
Pressure of the larger bubble is higher than the smaller bubble
- C
Both bubbles have the same internal pressure
- D
AnswerCorrect option: A. Internal pressure of the smaller bubble is higher than the internal pressure of the larger bubble
(a)$\Delta P=\frac{4 T}{R} \therefore \Delta P \propto \frac{1}{R} \quad(T=\text { constant })$Hence, the internal pressure of smaller bubble is larger than that of larger bubble.
View full question & answer→MCQ 1071 Mark
A particle of mass $\mathrm{m}$ moving with horizontal speed $6 \mathrm{~m} / \mathrm{sec}$ as shown in figure. If $m \ll M$ then for one dimensional elastic collision, the speed of lighter particle after collision will be
- ✓
$2 \mathrm{~m} / \mathrm{sec}$ in original direction
- B
$2 \mathrm{~m} / \mathrm{sec}$ opposite to the original direction
- C
$4 \mathrm{~m} / \mathrm{sec}$ opposite to the original direction
- D
$4 \mathrm{~m} / \mathrm{sec}$ in original direction
AnswerCorrect option: A. $2 \mathrm{~m} / \mathrm{sec}$ in original direction
View full question & answer→MCQ 1081 Mark
If a long spring is stretched by $0.02 \mathrm{~m}$, its potential energy is $U$. If the spring is stretched by $0.1 \mathrm{~m}$, then its potential energy will be
- A
$\frac{U}{5}$
- B
$U$
- C
$5 \ U$
- ✓
$25\ \mathrm{U}$
AnswerCorrect option: D. $25\ \mathrm{U}$
(d) $U \propto x^2 \Rightarrow \frac{U_2}{U_1}=\left(\frac{x_2}{x_1}\right)^2=\left(\frac{0.1}{0.02}\right)^2=25 \therefore U_2=25 \ U$
View full question & answer→MCQ 1091 Mark
Two soap bubbles of radii $r_1$ and $r_2$ equal to $4 \mathrm{~cm}$ and $5 \mathrm{~cm}$ are touching each other over a common surface $S_1 S_2$ (shown in figure). Its radius will be

- A
$4 \mathrm{~cm}$
- ✓
$20 \mathrm{~cm}$
- C
$5 \mathrm{~cm}$
- D
$4.5 \mathrm{~cm}$
AnswerCorrect option: B. $20 \mathrm{~cm}$
(b) $\quad r=\frac{r_1 r_2}{r_1-r_2}=\frac{5 \times 4}{5-4}=20 \mathrm{~cm}$
View full question & answer→MCQ 1101 Mark
Two capillary tubes of same diameter are put vertically one each in two liquids whose relative densities are 0.8 and 0.6 and surface tensions are 60 and $50 \mathrm{dyne} / \mathrm{cm}$ respectively Ratio of heights of liquids in the two tubes $\frac{h_1}{h_2}$ is
- A
$\frac{10}{9}$
- B
$\frac{3}{10}$
- C
$\frac{10}{3}$
- ✓
$\frac{9}{10}$
AnswerCorrect option: D. $\frac{9}{10}$
(d) Ascent formula $h=\frac{2 T \cos \theta}{r d g}$
$ \Rightarrow \frac{h_1}{h_2}=\frac{T_1}{T_2} \times \frac{d_2}{d_1} \quad(r, \theta \text { and } g \text { are constants })$
$ =\frac{60}{50} \times \frac{0.6}{0.8}=\frac{9}{10}$
View full question & answer→MCQ 1111 Mark
A ball of mass $m$ moving with velocity $V$, makes a head on elastic collision with a ball of the same mass moving with velocity $2 \mathrm{~V}$ towards it. Taking direction of $V$ as positive velocities of the two balls after collision are
- A
$-V$ and $2 V$
- B
$2 V$ and $-V$
- C
$V$ and $-2 V$
- ✓
$-2 V$ and $V$
AnswerCorrect option: D. $-2 V$ and $V$
(d) Due to elastic collision of bodies having equal mass, their velocities get interchanged.
View full question & answer→MCQ 1121 Mark
The radii of two soap bubbles are $r$ and $r$. In isothermal conditions, two meet together in vaccum. Then the radius of the resultant bubble is given by
AnswerCorrect option: C. $R^2=r_1^2+r_2^2$
View full question & answer→MCQ 1131 Mark
Water rises to a height $h$ in a capillary at the surface of earth. On the surface of the moon the height of water column in the same capillary will be
- ✓
$6 h$
- B
$\frac{1}{6} h$
- C
$h$
- D
Answer(a) $h=\frac{2 T \cos \theta}{r d g} \therefore h \propto \frac{1}{g}$As $g_m=\frac{g_e}{6} \therefore h_m=6 h_e$
View full question & answer→MCQ 1141 Mark
A particle of mass $m$ moving with a velocity $\vec{V}$ makes a head on elastic collision with another particle of same mass initially at rest. The velocity of the first particle after the collision will be
- A
$\vec{V}$
- B
$-\vec{V}$
- C
$-2 \vec{V}$
- ✓
Answer(d) In perfectly elastic head on collision of equal masses velocities gets interchanged
View full question & answer→MCQ 1151 Mark
If a lighter body $($mass $M_1$ and velocity $V_1 )$ and a heavier body $($mass $M_2$ and velocity $V_2 )$ have the same kinetic energy, then
- A
$M_2 V_2$
- B
$M_2 V_2=M_1 V_1$
- C
$M_2 V_1=M_1 V_2$
- ✓
$M_2 V_2>M_1 V_1$
AnswerCorrect option: D. $M_2 V_2>M_1 V_1$
$M_2 V_2>M_1 V_1$
View full question & answer→MCQ 1161 Mark
The amount of work done in blowing a soap bubble such that its diameter increases from $d$ to $D$ is ( $T$ = surface tension of the solution)
- A
$4 \pi\left(D^2-d^2\right) T$
- B
$8 \pi\left(D^2-d^2\right) T$
- C
$\pi\left(D^2-d^2\right) T$
- ✓
$2 \pi\left(D^2-d^2\right) T$
AnswerCorrect option: D. $2 \pi\left(D^2-d^2\right) T$
$ W=T \times 8 \pi\left(r_2^2-r_1^2\right)=T \times 8 \pi\left(\frac{D^2}{4}-\frac{d^2}{4}\right)$
$ =2 \pi\left(D^2-d^2\right) T$
View full question & answer→MCQ 1171 Mark
When two soap bubbles of radius $r_1$ and $r_2\left(r_2>r_1\right)$ coalesce, the radius of curvature of common surface is
AnswerCorrect option: C. $\frac{r_1 r_2}{r_2-r_1}$
View full question & answer→MCQ 1181 Mark
A force $\boldsymbol{F}=(5 \hat{\boldsymbol{i}}+3 \hat{\boldsymbol{j}})$ newton is applied over a particle which displaces it from its origin to the point $\boldsymbol{r}=(2 \hat{i}-1 \hat{\boldsymbol{j}})$ metres. The work done on the particle is
Answer(c) $W=\vec{F} \cdot \vec{s}=(5 \hat{i}+3 \hat{j}) \cdot(2\hat{i}\hat{j})=10-3=7\mathrm{~J}$
View full question & answer→MCQ 1191 Mark
The work done in blowing a soap bubble of $10 \mathrm{~cm}$ radius is (Surface tension of the soap solution is $\frac{3}{100} \mathrm{~N} / \mathrm{m}$ )
- ✓
$75.36 \times 10^{-4}$ joule
- B
$37.68 \times 10^{-4}$ joule
- C
$150.72 \times 10^{-4}$ joule
- D
AnswerCorrect option: A. $75.36 \times 10^{-4}$ joule
(a) $W=8 \pi R^2 T=8 \times 3.14 \times\left(10 \times 10^{-2}\right) \times \frac{3}{100}$
View full question & answer→MCQ 1201 Mark
A body of mass $m$ having an initial velocity $v$, makes head on collision with a stationary body of mass $M$. After the collision, the body of mass $m$ comes to rest and only the body having mass $M$ moves. This will happen only when
- A
$m \gg M$
- B
$m<<\ M$
- ✓
$m=M$
- D
$m=\frac{1}{2} M$
Answer(c) Velocity exchange takes place when the masses of bodies are equal
View full question & answer→MCQ 1211 Mark
If temperature increases, the surface tension of a liquid
View full question & answer→MCQ 1221 Mark
If the kinetic energy of a body increases by $0.1 \%$, the percent increase of its momentum will be
- ✓
$0.05 \%$
- B
$0.1 \%$
- C
$1.0 \%$
- D
$10 \%$
AnswerCorrect option: A. $0.05 \%$
(a) $P=\sqrt{2 m E} \therefore P \propto \sqrt{E}$Percentage increase in $P=\frac{1}{2}$ (percentage increase in $E$ )$=\frac{1}{2}(0.1 \%)=0.05 \%$
View full question & answer→MCQ 1231 Mark
The potential energy of a molecule on the surface of liquid compared to one inside the liquid is
View full question & answer→MCQ 1241 Mark
A body of mass $m \mathrm{~kg}$ is lifted by a man to a height of one metre in $30 \mathrm{sec}$. Another man lifts the same mass to the same height in 60 sec. The work done by them are in the ratio
- A
$1: 2$
- ✓
$1: 1$
- C
$2: 1$
- D
$4: 1$
AnswerCorrect option: B. $1: 1$
(b) Work done does not depend on time.
View full question & answer→MCQ 1251 Mark
Force necessary to pull a circular plate of $5 \mathrm{~cm}$ radius from water surface for which surface tension is 75 dynes $/ \mathrm{cm}$, is
AnswerCorrect option: D. $750 \pi$ dynes
(d) The total length of the circular plate on which the force will act $=2 \pi R$Force to pull $=2 \pi R T=2 \times \pi \times 5 \times 75=750 \pi$ dynes
View full question & answer→MCQ 1261 Mark
Surface tension of a soap solution is $1.9 \times 10^{-2} \mathrm{~N} / \mathrm{m}$. Work done in blowing a bubble of $2.0 \mathrm{~cm}$ diameter will be
- A
$7.6 \times 10^{-6} \pi$ joule
- ✓
$15.2 \times 10^{-6} \pi$ joule
- C
$1.9 \times 10^{-6} \pi$ joule
- D
$1 \times 10^{-4}$ joule
AnswerCorrect option: B. $15.2 \times 10^{-6} \pi$ joule
(b) $W=8 \pi R^2 T=8 \pi \times\left(1 \times 10^{-2}\right)^2 \times 1.9 \times 10^{-2}=15.2 \times 10^{-6} \pi J$
View full question & answer→MCQ 1271 Mark
Pressure inside two soap bubbles are $1.01$ and $1.02$ atmospheres. Ratio between their volumes is
- A
$102: 101$
- B
$(102):(101)$
- ✓
$8: 1$
- D
$2: 1$
AnswerCorrect option: C. $8: 1$
Outside pressure $=1 \mathrm{~atm}$
Pressure inside first bubble $=1.01 \mathrm{~atm}$
Pressure inside second bubble $=1.02 \mathrm{~atm}$
Excess pressure $\Delta P_1=1.01-1=0.01 \mathrm{~atm}$
Excess pressure $\Delta P_2=1.02-1=0.02 \mathrm{~atm}$
$\Delta P \propto \frac{1}{r} \Rightarrow r \propto \frac{1}{\Delta P}\Rightarrow \frac{r_1}{r_2}=\frac{\Delta P_2}{\Delta P_1}=\frac{0.02}{0.01}=\frac{2}{1}$
Since $V=\frac{4}{3} \pi r^3 \quad \therefore \frac{V_1}{V_2}=\left(\frac{r_1}{r_2}\right)^3=\left(\frac{2}{1}\right)^3=\frac{8}{1}$
View full question & answer→MCQ 1281 Mark
Water rises upto $10 \mathrm{~cm}$ height in a long capillary tube. If this tube is immersed in water so that the height above the water surface is only $8 \mathrm{~cm}$, then
AnswerCorrect option: B. Water rises upto upper end and forms a spherical surface
View full question & answer→MCQ 1291 Mark
A square frame of side $\mathrm{L}$ is dipped in a liquid. On taking out, a membrane is formed. If the surface tension of the liquid is $T$, the force acting on the frame will be
- A
$2 T L$
- B
$4 T L$
- ✓
$8 T L$
- D
$10 \mathrm{TL}$
AnswerCorrect option: C. $8 T L$
(c) Force on each side $=2 T L$ (due to two surfaces)$\therefore$ Force on the frame $=4(2 T L)=8 T L$
View full question & answer→MCQ 1301 Mark
A long cylindrical glass vessel has a small hole of radius ' $r$ ' at its bottom. The depth to which the vessel can be lowered vertically in the deep water bath $($surface tension $T )$ without any water entering inside is
- A
$477 \rho r g$
- B
$377 \rho r g$
- ✓
$27 / \rho r g$
- D
$\mathrm{T} / \rho r g$
AnswerCorrect option: C. $27 / \rho r g$
$h d g=\frac{2 T}{r} \Rightarrow h=\frac{2 T}{r d g}$
View full question & answer→MCQ 1311 Mark
The excess of pressure inside a soap bubble than that of the outer pressure is
- A
$\frac{2 T}{r}$
- ✓
$\frac{4 T}{r}$
- C
$\frac{T}{2 r}$
- D
$\frac{T}{r}$
AnswerCorrect option: B. $\frac{4 T}{r}$
View full question & answer→MCQ 1321 Mark
In the glass capillary tube, the shape of the surface of the liquid depends upon
- A
Only on the cohesive force of liquid molecules
- B
Only on the adhesive force between the molecules of glass and liquid
- ✓
Only on relative cohesive and adhesive force between the atoms
- D
Neither on cohesive nor on adhesive force
AnswerCorrect option: C. Only on relative cohesive and adhesive force between the atoms
View full question & answer→MCQ 1331 Mark
The surface tension of a soap solution is $2 \times 10^{-2} \mathrm{~N} / \mathrm{m}$. To blow a bubble of radius $1 \mathrm{~cm}$, the work done is
- A
$4 \pi \times 10^{-6} J$
- B
$8 \pi \times 10^{-6} \mathrm{~J}$
- C
$12 \pi \times 10^{-6} J$
- ✓
$16 \pi \times 10^{-6} \mathrm{~J}$
AnswerCorrect option: D. $16 \pi \times 10^{-6} \mathrm{~J}$
(d) $W=8 \pi R^2 T=8 \times \pi \times\left(10^{-2}\right)^2 \times 2 \times 10^{-2}=16 \pi \times 10^{-6} J$
View full question & answer→MCQ 1341 Mark
The excess pressure due to surface tension in a spherical liquid drop of radius $r$ is directly proportional to
- A
$r$
- B
$r^2$
- ✓
$r^{-1}$
- D
$r^{-2}$
AnswerCorrect option: C. $r^{-1}$
View full question & answer→MCQ 1351 Mark
The angle of contact between glass and mercury is
- A
$0^{\circ}$
- B
$30$
- C
$90$
- ✓
$135$
View full question & answer→MCQ 1361 Mark
The radius of a soap bubble is increased from $\frac{1}{\sqrt{\pi}} \mathrm{cm}$ to $\frac{2}{\sqrt{\pi}} \mathrm{cm}$. If the surface tension of water is $30$ dynes per $\mathrm{cm}$, then the work done will be
- A
$180$ ergs
- B
$360$ ergs
- ✓
$720$ ergs
- D
$960$ ergs
AnswerCorrect option: C. $720$ ergs
$ W=8 \pi T\left(r_2^2-r_1^2\right)=8 \pi T\left[\left(\frac{2}{\sqrt{\pi}}\right)^2-\left(\frac{1}{\sqrt{\pi}}\right)^2\right] \therefore W=8 \times \pi \times 30 \times \frac{3}{\pi}=720\ \mathrm{erg}$
View full question & answer→MCQ 1371 Mark
Two bodies of masses $m_1$ and $m_2$ have equal kinetic energies. If $p_1$ and $p_2$ are their respective momentum, then ratio $p_1: p_2$ is equal to
- A
$m_1: m_2$
- B
$m_2: m_1$
- ✓
$\sqrt{m_1}: \sqrt{m_2}$
- D
$m_1^2: m_2^2$
AnswerCorrect option: C. $\sqrt{m_1}: \sqrt{m_2}$
(c) $\quad P=\sqrt{2 m E} \quad \therefore P\propto\sqrt{m} (if)(E)=$ const
$(\therefore\frac{P_1}{P_2}=\sqrt{\frac{m_1}{m_2}})$
View full question & answer→MCQ 1381 Mark
A light and a heavy body have equal momenta. Which one has greater $K.E$
View full question & answer→MCQ 1391 Mark
Two capillary tubes $P$ and $Q$ are dipped in water. The height of water level in capillary $P$ is $2 / 3$ to the height in $Q$ capillary. The ratio of their diameters is
- ✓
$2: 3$
- B
$3: 2$
- C
$3: 4$
- D
$4: 3$
AnswerCorrect option: A. $2: 3$
(b) $r \propto \frac{1}{h} \Rightarrow \frac{r_P}{r_Q}=\frac{h_Q}{h_P}=\frac{h}{\frac{2}{3} h}=\frac{2}{3}$
View full question & answer→MCQ 1401 Mark
A mercury drop does not spread on a glass plate because the angle of contact between glass and mercury is
View full question & answer→MCQ 1411 Mark
The surface tension of a liquid at its boiling point
- ✓
- B
- C
is equal to the value at room temperature
- D
is half to the value at the room temperature
View full question & answer→MCQ 1421 Mark
Work done in splitting a drop of water of $1 \mathrm{~mm}$ radius into 10 droplets is (Surface tension of water $=72 \times 10^{-3} \mathrm{~J} / \mathrm{m}^2$ )
- A
$9.58 \times 10^{-5} J$
- ✓
$8.95 \times 10^{-5} J$
- C
$5.89 \times 10^{-5} J$
- D
$5.98 \times 10^{-6} J$
AnswerCorrect option: B. $8.95 \times 10^{-5} J$
(b) Work done in splitting a water drop of radius $R$ into $n$ drops of equal size $=4 \pi R^2 T\left(n^{1 / 3}-1\right)$$\begin{aligned}& =4 \pi \times\left(10^{-3}\right)^2 \times 72 \times 10^{-3} \times\left(10^{6 / 3}-1\right) \\& =4 \pi \times 10^{-6} \times 72 \times 10^{-3} \times 99=8.95 \times 10^{-5} \mathrm{~J}\end{aligned}$
View full question & answer→MCQ 1431 Mark
A pin or a needle floats on the surface of water, the reason for this is
View full question & answer→MCQ 1441 Mark
The meniscus of mercury in the capillary tube is
View full question & answer→MCQ 1451 Mark
The kinetic energy of a body of mass $3 \mathrm{~kg}$ and momentum $2 \mathrm{Ns}$ is
AnswerCorrect option: B. $\frac{2}{3} \mathrm{~J}$
(b) $E=\frac{P^2}{2 m}=\frac{4}{2 \times 3}=\frac{2}{3} \mathrm{~J}$
View full question & answer→MCQ 1461 Mark
The potential energy of a weight less spring compressed by a distance a is proportional to
- A
$a$
- ✓
$a^2$
- C
$a^{-2}$
- D
$a^0$
Answer(b) Potential energy of spring $=\frac{1}{2} K x^2$$\therefore P E\propto x^2\Rightarrow P E \propto a^2$
View full question & answer→MCQ 1471 Mark
In an explosion a body breaks up into two pieces of unequal masses. In this
- ✓
Both parts will have numerically equal momentum
- B
Lighter part will have more momentum
- C
Heavier part will have more momentum
- D
Both parts will have equal kinetic energy
AnswerCorrect option: A. Both parts will have numerically equal momentum
(a) Both part will have numerically equal momentum and lighter part will have more velocity.
View full question & answer→MCQ 1481 Mark
A bullet of mass $m$ moving with velocity $v$ strikes a block of mass $M$ at rest and gets embedded into it. The kinetic energy of the composite block will be
- ✓
$\frac{1}{2} m v^2 \times \frac{m}{(m+M)}$
- B
$\frac{1}{2} m v^2 \times \frac{M}{(m+M)}$
- C
$\frac{1}{2} m v^2 \times \frac{(M+m)}{M}$
- D
$\frac{1}{2} M v^2 \times \frac{m}{(m+M)}$
AnswerCorrect option: A. $\frac{1}{2} m v^2 \times \frac{m}{(m+M)}$
(a) By conservation of momentum, $\quad m v+M \times 0=(m+M) V$ Velocity of compositeblock$V=\left(\frac{m}{m+M}\right) v$K.E. of composite block $=\frac{1}{2}(M+m) V^2$$=\frac{1}{2}(M+m)\left(\frac{m}{M+m}\right)^2 v^2=\frac{1}{2} m v^2\left(\frac{m}{m+M}\right)$
View full question & answer→MCQ 1491 Mark
A film of water is formed between two straight parallel wires of length $10 \mathrm{~cm}$ each separated by $0.5 \mathrm{~cm}$. If their separation is increased by $1 \mathrm{~mm}$ while still maintaining their parallelism, how much work will have to be done $\left(\right.$ Surface tension of water $=7.2 \times 10^{-2} \mathrm{~N} / \mathrm{m}$ )
- A
$7.22 \times 10^{-6}$ Joule
- ✓
$1.44 \times 10^{-5}$ Joule
- C
$2.88 \times 10^{-5}$ Joule
- D
$5.76 \times 10^{-5}$ Joule
AnswerCorrect option: B. $1.44 \times 10^{-5}$ Joule
$ \text { Increment in area of soap film }=A_2-A_1 $
$ =2 \times[(10 \times 0.6)-(10 \times 0.5)] \times 10^{-4}=2 \times 10^{-4} \mathrm{~m}^2 $
$ \text { Work done }=T \times \Delta A$
$ =7.2 \times 10^{-2} \times 2 \times 10^{-4}=1.44 \times 10^{-5} \mathrm{~J}$
View full question & answer→MCQ 1501 Mark
If the momentum of a body increases by $0.01 \%$, its kinetic energy will increase by
- A
$0.01 \%$
- ✓
$0.02 \%$
- C
$0.04 \%$
- D
$0.08 \%$
AnswerCorrect option: B. $0.02 \%$
(b) $E \propto P^2$ (if $m=$ constant)Percentage increase in $E=2$ (Percentage increase in $P$ )$=2 \times 0.01 \%=0.02 \%$
View full question & answer→