Find the ratio of the magnitude of the electric force
Question: Find the ratio of the magnitude of the electric force to the gravitational force acting between two protons. Solution:...
Read More →The force with which the earth attracts an object
Question: The force with which the earth attracts an object is called the weight of the object. Calculate the weight of the moon from the following data: The universal constant of gravitation $G=6.67 \times 10^{-11} \mathrm{~N}-\mathrm{m}^{2} / \mathrm{kg}$, mass of the moon $=7.36 \times 10^{22} \mathrm{~kg}$, mass of the earth $=6 \times 10^{24} \mathrm{~kg} \mathrm{~ a n d ~ t h e ~ d i s t a n c e ~ b e t w e e n ~ t h e ~ e a r t h ~ a n d ~ t h e ~ m o o n = 3 . 8}$ $\mathrm{km}$. Solution...
Read More →Two charged particles placed at a separation of
Question: Two charged particles placed at a separation of $20 \mathrm{~cm}$ exert $20 \mathrm{~N}$ of Coulomb force on each other. What will be the force if the separation is increased to $25 \mathrm{~cm}$ ? Solution:...
Read More →A satellite is projected vertically upwards from
Question: A satellite is projected vertically upwards from an earth station. At what height above the earth's surface will the force on the satellite due to the earth be reduced to half its value at the earth station? (Radius of the earth is $6400 \mathrm{~km}$.) Solution:...
Read More →A body builder exerts a force of
Question: A body builder exerts a force of $150 \mathrm{~N}$ against a bullworker and compresses it by $20 \mathrm{~cm}$. Calculate the spring constant of the spring in the bullworker. Solution:...
Read More →A monkey is sitting on a tree limb.
Question: A monkey is sitting on a tree limb. The limb exerts a normal force of $48 \mathrm{~N}$ and a frictional force of $20 \mathrm{~N}$. Find the magnitude of the total force exerted by the limb on the monkey. Solution:...
Read More →Two spherical bodies,
Question: Two spherical bodies, each of mass $50 \mathrm{~kg}$, are placed at a separation of $20 \mathrm{~cm}$. Equal charges are placed on the bodies and it is found that the force of Coulomb repulsion equals the gravitational attraction in magnitude. Find the magnitude of the charge placed on either body. Solution:...
Read More →At what distance should two charges,
Question: At what distance should two charges, each equal to $1 \mathrm{C}$, be placed so that the force between them equals your weight? Solution:...
Read More →Calculate the force with which you attract the earth.
Question: Calculate the force with which you attract the earth. Solution: Force acting on us $=\mathrm{mg}$ Let $m=60 \mathrm{~kg}$ Then, $F=W=m \times g=60 \times 10$ $\mathrm{F}=600 \mathrm{~N}$....
Read More →The gravitational force acting on a particle of
Question: The gravitational force acting on a particle of $1 \mathrm{~g}$ due to a similar particle is equal to $6.67 \times 10^{-11} \mathrm{~N}$. Calculate the separation between the particles. Solution:...
Read More →Action and reaction
Question: Action and reaction (a) act on two different objects (b) have equal magnitude (c) have opposite directions (d) have resultant zero Solution: According to the third law of motion, every action has equal and opposite reaction. Thus, action and reaction act on different objects, have equal magnitude, have opposite direction and have resultant zero. (a), (b), (c), (d)...
Read More →Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: If the points $A(3,-2), B(k, 2)$ and $C(8,8)$ are collinear then the value of $k$ is A. 2 B. $-3$ C. 5 D. $-4$ Solution: $\Rightarrow 10 k-50=0$ $\Rightarrow k=5$...
Read More →The two ends of a spring are displaced along the length of the spring.
Question: The two ends of a spring are displaced along the length of the spring. All displacements have equal magnitudes. In which case or cases the tension or compression in the spring will have a maximum magnitude? (a) the right end is displaced towards right and the left end towards left (b) both ends are displaced towards right (c) both ends are displaced towards left (d) the right end is displaced towards left and the left end towards right. Solution: Maximum magnitude in tension is when th...
Read More →Which of the following systems may be adequately described by classical physics?
Question: Which of the following systems may be adequately described by classical physics? (a) motion of a cricket ball (b) motion of a dust particle (c) a hydrogen atom (d) a neutron changing to a proton Solution: Classical physics is used generally for heavenly bodies and do not work for smaller size particle. Thus motion od cricket ball, motion of dust particles is adequately described by classical physics. (a), (b)...
Read More →If all matter were made of electrically neutral particles such
Question: If all matter were made of electrically neutral particles such as neutrons (a) there would be no force of friction (b) there would be no tension in the string (c) it would not be possible to sit on a chair (d) the earth could not move around the sun Solution: If all matter were made of electrically neutral particles, then there would be no friction, no tension in the string and also it would not be possible to sit on a chair. But earth could move around the sun as it is due to gravitat...
Read More →Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: The vertices of a a $A B C$ are $A(-2,4), B(2,-6)$ and $C(5,4)$. The area of a $A B C$ is A. $17.5 \mathrm{sq}$ units B. $35 \mathrm{sq}$ units C. $32 \mathrm{sq}$ units D. $28 \mathrm{sq}$ units Solution: To find: Area of $A B C$...
Read More →Mark the correct statements:
Question: Mark the correct statements: (a) The nuclear force between two protons is always greater than the electromagnetic force between them. (b) The electromagnetic force between two protons is always greater than the gravitational force between them. (c) The gravitational force between two protons may be greater than the nuclear force between them. (d) Electromagnetic force between two protons may be greater than the nuclear force acting between them Solution: Electromagnetic force is greate...
Read More →A proton exerts a force on a proton which is
Question: A proton exerts a force on a proton which is (a) gravitational (b) electromagnetic (c) nuclear (d) weak Solution: Proton exerts gravitational, electromagnetic and nuclear force on a proton because proton is a charges particle (a), (b), (c)...
Read More →A neutron exerts a force on a proton which is
Question: A neutron exerts a force on a proton which is (a) gravitational (b) electromagnetic (c) nuclear (d) weak Solution: Neutron exerts gravitational force and nuclear force on proton because neutron is uncharged particle. (a),(c)...
Read More →A 60 kg man pushes a 40 kg man by a force
Question: A 60 kg man pushes a 40 kg man by a force of 60 N.I The 40 kg man has pushed the other man with a force of (a) 40 N (b) 0 (c) 60 N (d) 20 N Solution: (c) 60 N...
Read More →The sum of all electromagnetic forces between different particles
Question: The sum of all electromagnetic forces between different particles of a system of charged particles is zero (a) only if all the particles are positively charged (b) only if all the particles are negatively charged (c) only if half the particles are positively charged half are negatively charged (d) irrespective of the signs of the charges Solution: (d) irrespective of the signs of the charges...
Read More →Let E, G and N represent the magnitudes of electromagnetic,
Question: Let $E, G$ and $N$ represent the magnitudes of electromagnetic, gravitational and nuclear forces between two electrons at a given separation. Then (a) $\mathrm{N}\mathrm{E}\mathrm{G}$ (b) $ENG$ (c) $\mathrm{G}\mathrm{N}\mathrm{E}$ (d) $EGN$ Solution: (d) $EGN$...
Read More →When Neils Bohr shook hand with Werner Heisenberg,
Question: WhenNeilsBohr shook hand with Werner Heisenberg, what kind of force they exerted? (a) Gravitational (b) Electromagnetic (c) Nuclear (d) Weak Solution: (b) Electromagnetic...
Read More →Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: The solution set of the equation $\left|\begin{array}{ccc}3 x-8 3 3 \\ 3 3 x-8 3 \\ 3 3 3 x-8\end{array}\right|=0$ is A. $\left\{\frac{2}{3}, \frac{8}{3}\right\}$ B. $\left\{\frac{2}{3}, \frac{11}{3}\right\}$ C. $\left\{\frac{3}{2}, \frac{8}{3}\right\}$ D. None of these Solution: To find: Value of $x$...
Read More →Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: The solution set of the equation $\left|\begin{array}{lll}a+x a-x a-x \\ a-x a+x a-x \\ a-x a-x a+x\end{array}\right|=0$ is A. $\{a, 0\}$ B. $\{3 a, 0\}$ C. $\{a, 3 a\}$ D. None of these Solution:...
Read More →