Explore topic-wise MCQs in Physics.

This section includes 27 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.

1.

The resistance R =\[\frac{V}{i}\] where V= 100 \[\pm \]5 volts and  i = 10 \[\pm \]0.2 amperes. What is the total error in R   

A. 5% 
B.  7%
C. If assertion is true but reason is false.
D.    \[\frac{5}{2}\]%
Answer» C. If assertion is true but reason is false.
2.

Assertion:   Units of Rydberg constant R are m?1 Reason:     It follows from Bohr?s formula \[\bar{v}=R\left( \frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}} \right)\], where the symbols have their usual meaning.

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.   If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.  
D.   If the assertion and reason both are false.
E. If assertion is false but reason is true.
Answer» B.   If both assertion and reason are true but reason is not the correct explanation of the assertion.
3.

The number of significant figures in all the given numbers 25.12, 2009, 4.156 and \[1.217\times {{10}^{-4}}\] is      [Pb. PET 2003]

A.  1   
B. 2
C. If assertion is true but reason is false.
D.    4
Answer» E.
4.

The radius of a sphere is (5.3 ± 0.1) cm. The percentage error in its volume is 

A.  \[\frac{0.1}{5.3}\times 100\]
B.    \[3\times \frac{0.1}{5.3}\times 100\]  
C. In the car to the side of the person  
D.    \[3+\frac{0.1}{5.3}\times 100\]
Answer» C. In the car to the side of the person  
5.

A force \[F\] is given by \[F=at+b{{t}^{2}}\], where \[t\] is time. What are the dimensions of \[a\] and \[b\]  [AFMC 2001; BHU 1998, 2005]

A. \[ML{{T}^{-3}}\] and \[M{{L}^{2}}{{T}^{-4}}\]
B.   \[ML{{T}^{-3}}\] and \[ML{{T}^{-4}}\]
C. None of the strings will break  
D. \[ML{{T}^{-4}}\] and \[ML{{T}^{1}}\]
Answer» C. None of the strings will break  
6.

The physical quantity that has no dimensions [EAMCET (Engg.) 1995]

A. Angular Velocity   
B.   Linear momentum
C. \[{{150}^{\text{o}}}\]  
D. Strain
Answer» E.
7.

Dimensions of coefficient of viscosity are [AIIMS 1993; CPMT 1992; Bihar PET 1984; MP PMT 1987, 89, 91; AFMC 1986;  CBSE PMT 1992; KCET 1994; DCE 1999; AIEEE 2004; DPMT 2004]

A. \[M{{L}^{2}}{{T}^{-2}}\]
B.   \[M{{L}^{2}}{{T}^{-1}}\]
C. \[150{}^\circ \]   
D. \[MLT\]
Answer» D. \[MLT\]
8.

The dimensions of permittivity \[{{\varepsilon }_{0}}\] are   [MP PET 1997; AIIMS-2004; DCE-2003]

A. \[{{A}^{2}}{{T}^{2}}{{M}^{-1}}{{L}^{-3}}\] 
B.   \[{{A}^{2}}{{T}^{4}}{{M}^{-1}}{{L}^{-3}}\]
C. \[-5\sqrt{2},\,\,\pi /3\]
D. \[{{A}^{2}}{{T}^{-4}}{{M}^{-1}}{{L}^{-3}}\]
Answer» C. \[-5\sqrt{2},\,\,\pi /3\]
9.

Which pair has the same dimensions [EAMCET 1982; CPMT 1984, 85; Pb. PET 2002; MP PET 1985]

A.  Work and power  
B. Density and relative density
C. \[T=70.8N\] and \[{T}'=58.8N\]
D. Stress and strain
Answer» D. Stress and strain
10.

Dimensions of permeability are     [CBSE PMT 1991; AIIMS 2003]

A. \[{{A}^{-2}}{{M}^{1}}{{L}^{1}}{{T}^{-2}}\]
B.   \[ML{{T}^{-2}}\]
C. Upthrust of the air which will be equal to the weight of the air having the same volume as the plane  
D. \[{{A}^{-1}}ML{{T}^{2}}\]
Answer» B.   \[ML{{T}^{-2}}\]
11.

A small steel ball of radius \[r\] is allowed to fall under gravity through a column of a viscous liquid of coefficient of viscosity \[\eta \]. After some time the velocity of the ball attains a constant value known as terminal velocity \[{{v}_{T}}\]. The terminal velocity depends on (i) the mass of the ball \[m\], (ii) \[\eta \], (iii) \[r\] and (iv) acceleration due to gravity \[g\]. Which of the following relations is dimensionally correct [CPMT 1992; CBSE PMT 1992; NCERT 1983; MP PMT 2001]

A.  \[{{v}_{T}}\propto \frac{mg}{\eta r}\]
B.  \[{{v}_{T}}\propto \frac{\eta r}{mg}\]
C. \[({{F}_{2}}-{{F}_{3}})/m\]
D. \[{{v}_{T}}\propto \frac{mgr}{\eta }\]
Answer» B.  \[{{v}_{T}}\propto \frac{\eta r}{mg}\]
12.

Which of the following quantities has the same dimensions as that of energy [AFMC 1991; CPMT 1976; DPMT 2001]

A. Power 
B.   Force
C.   12 N    
D. Work
Answer» E.
13.

A spherical body of mass \[m\] and radius \[r\] is allowed to fall in a medium of viscosity \[\eta \].  The time in which the velocity of the body increases from zero to 0.63 times the terminal velocity \[(v)\] is called time constant \[(\tau )\]. Dimensionally \[\tau \] can be represented by      [AIIMS 1987]

A.  \[\frac{m{{r}^{2}}}{6\pi \eta }\] 
B.  \[\sqrt{\left( \frac{6\pi mr\eta }{{{g}^{2}}} \right)}\]
C. 0.1 m/s  
D. None of the above
Answer» E.
14.

The frequency of vibration \[f\] of a mass \[m\] suspended from a spring of spring constant \[K\]is given by a relation of this type \[f=C\,{{m}^{x}}{{K}^{y}}\]; where \[C\] is a dimensionless quantity. The value of \[x\] and \[y\] are       [CBSE PMT 1990]

A.  \[x=\frac{1}{2},\,y=\frac{1}{2}\] 
B.   \[x=-\frac{1}{2},\,y=-\frac{1}{2}\]
C. \[\frac{\rho V}{{{v}_{1}}+{{v}_{2}}}v_{1}^{2}\]    
D.   \[x=-\frac{1}{2},\,y=\frac{1}{2}\]
Answer» E.
15.

The dimensional formula for impulse is same as the dimensional formula for [CPMT 1982, 83; CBSE PMT 1993; UPSEAT 2001]

A. Momentum
B.   Force
C. \[\sqrt{{{(M+m)}^{2}}+{{m}^{2}}}g\]
D. Torque
Answer» B.   Force
16.

Out of following four dimensional quantities, which one quantity is to be called a dimensional constant? [KCET 2005]

A. Acceleration due to gravity
B.   Surface tension of water
C. \[\sec \alpha =3\]
D.   The velocity of light in vacuum
Answer» E.
17.

 Out of the following pair, which one does not have identical dimensions?     [AIEEE 2005]

A. Moment of inertia and moment of force
B.   Work and torque
C. C  
D.   Impulse and momentum
Answer» B.   Work and torque
18.

The dimensional formula for young's modulus is?  [BHU 2003; CPMT 2004]  

A. \[M{{L}^{-1}}{{T}^{-2}}\]  
B.   \[{{M}^{0}}L{{T}^{-2}}\]  
C. 50 m/s
D.   \[M{{L}^{2}}{{T}^{-2}}\]
Answer» B.   \[{{M}^{0}}L{{T}^{-2}}\]  
19.

Which of the following quantities is dimensionless?     [MP PET 2002]

A. Gravitational constant
B.   Planck's constant
C. 1 m/s    
D.   None
Answer» E.
20.

An object is moving through the liquid. The viscous damping force acting on it is proportional to the velocity. Then dimension of constant of proportionality is?    [Orissa JEE 2002]

A. \[M{{L}^{-1}}{{T}^{-1}}\]
B.   \[ML{{T}^{-1}}\]
C. 4 N
D.   \[M{{L}^{0}}{{T}^{-1}}\]
Answer» E.
21.

Which of the following represents the dimensions of Farad      [AMU (Med.) 2002]

A. \[{{M}^{-1}}{{L}^{-2}}{{T}^{4}}{{A}^{2}}\]
B.   \[M{{L}^{2}}{{T}^{2}}{{A}^{-2}}\]
C. The flow of air around the wings causes an upward force, which compensates for the force of gravity  
D. \[M{{T}^{-2}}{{A}^{-1}}\]
Answer» B.   \[M{{L}^{2}}{{T}^{2}}{{A}^{-2}}\]
22.

A physcial quantity \[x\] depends on quantities \[y\] and \[z\] as follows: \[x=Ay+B\tan Cz\], where \[A,\,B\] and \[C\]  are constants. Which of the following do not have the same dimensions [AMU (Engg.) 2001]

A. \[x\] and \[B\]  
B.   \[C\] and \[{{z}^{-1}}\]
C. If assertion is true but reason is false.  
D. \[x\] and \[A\]
Answer» E.
23.

A highly rigid cubical block \[A\] of small mass \[M\] and side \[L\] is fixed rigidly onto another cubical block \[B\]of the same dimensions and of low modulus of rigidity \[\eta \] such that the lower face of \[A\] completely covers the upper face of \[B\]. The lower face of \[B\]is rigidly held on a horizontal surface. A small force \[F\] is applied perpendicular to one of the side faces of \[A\]. After the force is withdrawn block \[A\] executes small oscillations. The time period of which is given by      [IIT 1992]

A.  \[2\pi \sqrt{\frac{M\eta }{L}}\]
B.   \[2\pi \sqrt{\frac{L}{M\eta }}\]
C. If assertion is true but reason is false.    
D.    \[2\pi \sqrt{\frac{M}{\eta L}}\]
Answer» E.
24.

If the acceleration due to gravity is \[10\,m{{s}^{-2}}\] and the units of length and time are changed in kilometer and hour respectively, the numerical value of the acceleration is   [Kerala PET 2002]

A. 360000
B.    72,000
C. If assertion is true but reason is false.  
D.   129600
Answer» E.
25.

Assertion:   Avogadro number is the number of atoms in one gram mole. Reason:     Avogadro number is a dimensionless constant.

A.   If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.  If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.  3   
D.    If the assertion and reason both are false.
E.   If assertion is false but reason is true.
Answer» D.    If the assertion and reason both are false.
26.

Assertion:   In\[y=A\sin (\omega \,t-kx),\]\[(\omega t-kx)\]is dimensionless. Reason:     Because dimension of \[\omega =[{{M}^{0}}{{L}^{0}}T].\]

A.   If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.  If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.  5.2% 
D.    If the assertion and reason both are false.
E.   If assertion is false but reason is true.
Answer» D.    If the assertion and reason both are false.
27.

Assertion: ?Light year? and ?Wavelength? both measure distance. Reason:  Both have dimensions of time.

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.   If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.  \[\frac{0.1\times 100}{3.53}\]
D.   If the assertion and reason both are false.
E. If assertion is false but reason is true.
Answer» D.   If the assertion and reason both are false.