1 1.5 2 2.5 Solution: the correct answer is A. 1 $ \frac{{{\beta }_{dc}}-{{\alpha }_{dc}}}{{{\alpha }_{dc}}.{{\beta }_{dc}}}=\frac{\frac{\alpha }{1-\alpha }-\alpha }{\frac{\alpha }{1-\alpha }\times...

A. cos2ϕ/2 B. cos2ϕ/4 C. cos2ϕ/3 D. cos2ϕ Solution: The correct answer is A. cos2ϕ/2 The intensity of two similar light waves propagating in the same direction with a phase difference is as follows:...

Solution: The correct answer is B. $ We\,know\,that: $ $ \tan \theta =\frac{{{n}_{2}}}{{{n}_{1}}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(1) $ $ {{n}_{1}}=1,\,\sin...

Solution: the correct answer is D. $ \frac{1}{{{C}_{initial}}}=\frac{1}{C}+\frac{1}{C} $ $ {{C}_{initial}}=\frac{C}{2} $ $ \frac{1}{{{C}_{final}}}=\frac{1}{KC}+\frac{1}{C} $ $...

400 W 800 W 600 W 200 W Solution: The correct answer is A 400 W Given : Vrms = 220 V, R = 18Ω and Z = 33Ω We get  P = 400W

10−1V/m 10−2V/m 10−3V/m 10−4V/m Solution: The correct answer is 2. 10−2V/m $ We\,have:\, $ $ \rho =40\times {{10}^{-8}}\,\Omega m\, $ $ I=0.2A $ $ A=8\times {{10}^{-6}}{{m}^{2}} $ $...

Both V and E increase Both V and E decrease V increases, E decreases V decreases, E increases Solution: The correct answer is B Both V and E decrease A dielectric capacitor with parallel plates....

λp ∝ λe λp ∝ λ2e λp ∝ √λe λp ∝ 1/λe Solution: The correct answer is A λp∝λe λe denotes the wavelength of the electron and λp denotes the wavelength of the proton. $ {{E}_{p}}=hv=\frac{hc}{{{\lambda...

(2) (1) (3) (4) Solution: The correct answer is  At resonance ω =1/√LC f = 1/2π√LC The impedance is highest at resonance, and the frequency and current are lowest.

1.8 eV 1.4 eV 1 eV 1.267 eV Solution: The solution is D 1.267 eV According to the Einstein's Photoelectric equation:

A. 0.25 A B. 0.50 A C. 0.75 A D. 1 A Solution: the correct answer is C. 0.75 A Magnetic induction inside the solenoid is given by: $ B=\frac{{{\mu }_{0}}NI}{L} $ $ Magnetic\,Flux\,: $ $ \phi...

  A.                    2×105A/m B.                     4×105A/m C.                      3×105A/m D.                    5×105A/m Solution: The correct answer is D. 5×105A/m $ Length\text{...

Repeater Modulation Attenuation Demodulation Solution: The correct answer is B. Modulation Modulation is the process of superimposing a signal on a high-frequency wave that functions as a carrier...

  A. d2/D B. d2/2D C. d2/3D D. d2/4D Solution: The correct answer is C. d2/3D Because the second minima occur right in front of one of the slits, y = d/2 $ For\text{ }second\text{...

1.4 m Wb 2.2 m Wb 2.7 m Wb 2.9 m Wb Solution: The correct solution is C. 2.7 m Wb We have, di/dt = 10 M = E/(di/dt) =15/10 Flux = Mi = 1.5 × 1.8 Flux =2.7mWb

(A) which is always operated in reverse bias (B) which is always operated in forward bias (C) in which photo current is independent of intensity of incident radiation (D) which may be operated in...

A.1/n2 B. n2 C.1/n D. n Solution: The correct answer is D. n The magnetic moment of an electron can be expressed as: μ = −(neh)/(4πme) The magnetic moment is directly proportional to the primary...

2 eV 4 eV 8 eV 6 eV Solution: The correct answer is D 6 eV E = (−13.6/4) + (13.6/1) = 10.2 So stopping potential equals to hv = ϕ(0) + Vs 10.2 − 4.2 = Vs Vs = 6 eV

1.258 1.269 1.310 1.286 Solution: The correct answer is D 1.286 The number of waves on the glass slab equals the number of waves in the water column. μghg = μwhw μw = μghg/hw = 1.5 × 67 μw = 1.286...

A. 0.2 $ \log _{e}^{2} $ B. 0.5 $ \log _{e}^{2} $ C. 0.6 $ \log _{e}^{2} $ D. 0.8 $ \log _{e}^{2} $ Solution: The correct answer is 0.5 $ \log _{e}^{2} $ $ {{N}_{0}}\lambda =10000 $ $ N\lambda =2500...

A. 10−2 m B. 10−1 m C. 2×10−2 m D. 2×10−1 m Solution: The correct answer is A. 10−2 m expression for the distance between the first two minimum on the other side is given by: = 2λD/d...

12 24 48 36 Solution: The correct answer is B. 24 let the resistance at right be R and at left be r $ \frac{r}{R}=\frac{{{l}_{x}}}{{{l}_{R}}}=\frac{40}{60} $ $ \frac{r+30}{R}=\frac{60}{40} $ $...

s/3 s/6 s/12 s/9 Solution: The correct answer is D. s/9 S = G/8 S = G/(n−1) Now, we get: G/8 = G/(n−1) ⇒ n = 9 When a galvanometer's range is increased nine times, its sensitivity drops to 1/9. S'=...

5μF 7μF 6μF 8μF Solution; The correct answer is A. 5μF Let the capacitance be C when connected in parallel combination, C1 = C + C + C = 3C when other was connected in series, we get: 1/Cf = 1/3.75...

v1−v2=v3 v1+v3=v2 v1+v2=v3 v1−v3=2v1 Solution: The correct answer is A. v1−v2=v3 $ The\,Balmer\,\lim it\,wavelength\,is: $ $ \frac{1}{{{\lambda }_{1}}}=R\left( \frac{1}{{{2}^{2}}}-\frac{1}{\infty }...

A. MgA2/2L B. MgA/2L C. MgA2/L D. 2MgA2/L Solution: The correct answer is A. MgA2/2L $ PE=\frac{m{{\omega }^{2}}{{x}^{2}}}{2} $ $ \omega =\sqrt{\frac{g}{L}}\,at\,extreme\,po\operatorname{int}\,x=A $...

is conserved increases decreases may increase or decrease Solution: The correct answer is A. is conserved The kinetic energy of a particle travelling in a vertical circle is converted into potential...

100,200,300,400,..... 100,300,500,700,.... 200,300,400,500,..... 200,400,600,800,..... Solution: The correct answer is D. 200,400,600,800,..... $ Fundamental\text{ }frequency\text{ }of\text{...

0 rad π/4 rad π/2 rad π rad Solution: The correct answer is D. pi rad The following is the displacement of the particle executing SHM. x = A coswt Differentiating w.r.t. time we get v = dx/dt v =−...

Solution: The correct answer is B. The following is the expression for acceleration due to gravity at a depth of d below the earth's surface. $ g'={{g}_{s}}\left( 1-\frac{d}{R} \right) $ $...

0.4 0.2857 0.2257 0.3557 Solution: The correct answer is B. 0.2857 $ Universal\text{ }gas\text{ }constant\text{ }is\text{ }given\text{ by:} $ $ R=nCp $ $ For\text{ }diatomic\text{ }molecule,\text{...

1.5 cm 2 cm 2.5 cm 3 cm Solution: The correct answer is A. 1.5 cm $ Upward\text{ }force\,is:\,\,\,F=105~dyne~=105\times {{10}^{-5}}~N $ $ Surface\text{ }tension\text{ }of\text{ }water~T=7\times...

1/3 1/5 1/4 1/6 Solution: The correct answer is A. 1/3 $ Fundamental\text{ }frequency\text{ }of\text{ }the\text{ }first\text{ }wire~\,is: $ $...

96 rad 48 rad 24 rad 72 rad Solution: The correct answer is 96 rad Angular acceleration is given by: α = 24/8 = 3 rad/s2 Now angular displacement becomes: θ = 0 + αt2/2 θ...

√14 m √2.8 m √1.4 m √0.7 m Solution: The correct answer is B. √2.8 m $ We\,have:\,\,m=2kg~~and\,~v=6m/s $ $ Total\text{ }kinetic\text{ }energy\text{ }of\text{ }the\text{ }sphere\text{...

Solution: The correct answer is B. $ change\text{ }in\text{ }length:\,~\delta L=L\alpha T $ $ final\text{ }length~\,{{L}_{f}}=L+\delta L $ Now, in order to limit the expansion, there must be a force...

A. 2nv0/v B. v/2nv0 C. v/nv0 D. nv0/v Solution: The correct answer is A. 2nv0/v $ \text{Making use of the }doppler\text{ }effect $ $ Case\text{ }I:~Observer\,is\text{ }approaching\text{ }the\text{...

The correct option is B. $ u=\omega \sqrt{({{A}^{2}}-{{x}^{2}})} $ $ \alpha =-{{\omega }^{2}}x $ $ v=\omega \sqrt{({{A}^{2}}-{{y}^{2}})} $ $ \beta =-{{\omega }^{2}}y $ $...

Solution: The correct answer is D. $ Initial\text{ }angular\text{ }momentum\text{ }of\text{ }the\text{ }system~is\,given\,by: $ $ {{L}_{i}}={{I}_{1}}{{\omega }_{1}}+{{I}_{2}}\omega \prime ~ $ $...

8n/15 4n/15 16n/15 32n/15 Solution: The correct answer is C. 16n/15 $ {{(\omega /4)}^{2}}={{\omega }^{2}}-2\alpha ~n(2\pi ) $ $ \therefore 2\alpha n(2\pi )={{\omega }^{2}}-\frac{{{\omega }^{2}}}{16}...

Solution: The correct answer is B. $ Let\text{ }the\text{ }tension\text{ }be\text{ }F.\,So, $ $ F-mg=ma\to F=m(g+a) $ $ Now,\,~T=\frac{F}{\pi {{r}^{2}}} $ $ r={{\left( \frac{m\left( g+a \right)}{\pi...

8 14 20 17 Solution: The correct answer is D. 17 $ The\,fundamental\text{ }frequencyfor\,closed\,pipe\,is: $ $ {{f}_{c}}=\frac{v}{4l} $ $ for\,open\,pipe:\,\,{{f}_{o}}=\frac{v}{2l} $ $ \therefore...

T1/T2 (T1/T2)2 (T2/T1)2 T2/T1 Solution: The correct answer is 2. (T1/T2)2  

Velocity V=1.5m/s Frequency F=0.2 Hz Wavelength λ=10 m Amplitude A=3 cm Solution: The correct answer is C. Wavelength λ=10 m $ Y=3\sin \left[ \pi \left( \frac{t}{3}-\frac{x}{5} \right)+\frac{\pi...

24 Kg m2/s 48 Kg m2/s 72 Kg m2/s 96 Kg m2/s Solution: The correct answer is C. 72 Kg m2/s $ {{w}_{f}}=w+\alpha t\to 0=60+\alpha \times 300 $ $ \alpha =\frac{-1}{5} $ $ now\text{ }to\text{...

L/6,L/2,5L/6 L/8,L/4,L/2 L/2,L/4,L/6 L/6,L/2,L/6 Solution: The correct answer is A. L/6,L/2,5L/6 $ For\text{ }second\text{ }overtone~:\frac{3\lambda }{2}=L $ $ first\text{ }maxima\text{ }will\text{...

2√2m 4√2m 6√2m 8√2m Solution: The correct answer is D. 8√2m $ We\,have~: $ $ x=A\,sin\omega t $ $ Upon\text{ }differentiating\text{ }both\text{ }side,\,we\,get: $ $ ~v=A\omega \,cos\omega t $ $...

2(R+h)/R (R+h)/2R (R+h)/R R/(R+h) Solution: The correct answer is 1. 2(R+h)/R

n2:1 n:1 3√n:1 √n:1 Solution: The correct answer is C. $ By\text{ }mass\text{ }conservation\text{ }new\text{ }radius\text{ }R\text{ }is~ $ $ R={{n}^{1/3}}r $ $ ratio\text{ }of\text{ }energy\text{...

Pm/KT KT/Pm Km/PT PK/Tm Solution: The correct answer is A. Pm/KT The ideal gas equation is PV = nRT, we can also write: PV = NKT here K is a Boltzmann constant Now we have: ρ = m/V = Nm/V putting...

0 4 5 6 Solution: The correct answer is A. 0 The frequency for a pipe closed at one end is given by: f = (n×v )/4L    v = speed of sound = 332m/s L = length of pipe = 83cm = 0.83m n = 0,1,2... f =...

h=2R h=3R h=5R h=7R Solution: The correct answer is D. h=7R   $ Escape\,velocity,\,{{v}_{e}}=\sqrt{\frac{2GM}{R}} $ $ v=\frac{{{v}_{e}}}{4}=\frac{1}{4}\sqrt{\frac{2GM}{R}} $ $ Centripetal\text{...

5 cm 20 cm 15 cm 10 cm Solution: The correct answer is D. 10cm We know that the magnetic field at a distance d from the magnet's centre on the axis is given as follows for a magnet of length 2l and...

F2L/2AY FL/2AY FL/AY F2L2/2AY Solution: The correct answer is 1. $ Energy,\,\,U=\frac{1}{2}\times stress\times strain\times volume $ $ Stress=\frac{F}{A} $ $ Strain=\frac{Stress}{Y}=\frac{F}{AY} $ $...

n √n n√2 n√5 Solution: The correct answer is A. n The number of waves is determined by the same harmonic. As a result, the needed number of waves is the same, n.

h2/mλ h2/2m2λ h2/2m2λ2 h2/2mλ2 Solution: $ \lambda =\frac{h}{mv} $ $ v=\frac{h}{m\lambda } $ $ K=\frac{1}{2}m{{v}^{2}}=\frac{1}{2}m{{\left( \frac{h}{m\lambda } \right)}^{2}} $ $...

(A) large and large (B) large and small (C) short and large (D) short and small Solution: The correct answer is (C) short and small Two convex lenses make up a compound microscope. The objective...

(1) (2) (3) (4) Solution: The correct answer is A. (1) The stopping potential is the amount of energy required to prevent an electron from reaching the outside world. Electrons are emitted from the...

28% 7% 21% 14% Solution: The correct option is D. 14%

Solution: The correct answer is C. $ Y=\frac{F/A}{\Delta l/l} $ $ \Delta l=\frac{Fl}{AY} $ $ \Delta l\,\alpha \,\frac{1}{A} $ $ m=Al\rho \Rightarrow m\,\alpha \,A $ $ Hence,\,\frac{\Delta...

100J 500J 700J 900J Solution: The correct answer is 2. 500 J Let, the heat transmitted per minute be given by H. Now, The total incident energy = energy absorbed + energy reflected + energy...

Solution: The correct answer is A. $ For\,series\,combination,\,equivalence\,capacitance\,=\,\frac{{{C}_{1}}}{{{N}_{1}}} $ $ ch\arg e,\,\,q=(3V)\frac{{{C}_{1}}}{{{N}_{1}}} $ $...

Solution: The correct answer is D. $ We\,have:\,\,g=\frac{G{{M}_{e}}}{{{R}^{2}}} $ $ Applying\text{ }law\text{ }of\text{ }conservation\text{ }of\text{ }mechanical\text{ }energy:- $ $...

1/2 (1/3)rd (1/4)th (1/8.5)th Solution: The correct answer is  The current through the galvanometer is given by $ {{i}_{1}}=\frac{{{R}_{s}}}{{{R}_{s}}+{{R}_{g}}}i $ where Rs = resistance of shunt...

(A) decreases while frequency increases (B) remains the same whereas frequency increases (C) increases and frequency also increases (D) decreases while frequency remains the same Solution; The...

independent of d directly proportional to d directly proportional to 1/√d directly proportional to √d Solution: The correct answer is A. independent of d The required electric field for the point...

g 3g 6g 4g Solution: The correct answer is B. 3g $ The\text{ }speed\text{ }when\text{ }a\text{ }string\text{ }is\text{ }horizontal,~\,v=\sqrt{3gr} $ $ Hence,\text{ }centripetal\text{...

(A) decreases (B) increases (C) becomes zero (D) first decreases and then increases Solution: The correct answer is (B) increases We know:  eVo = hν − ϕ where Vo gives the stopping potential, ν is...

P √5P √11P √13P Solution: The correct answer is √13P P1 = −3Pi  and P2 = 2Pj And m1 = m2 = m3 = m/3 And Pinitial = 0 Let the momentum of the third part be P3 Making use of the principle of...

Iω2/2 Iω2/4 Iω2/6 Iω2/8 Solution: The correct answer is Iω2/4 $ Initial\text{ }angular\text{ }momentum,\,{{L}_{1}}=I\omega  $ $ {{K}_{1}}=\frac{1}{2}I{{\omega }^{2}} $ We know that the block's...

2πm/s πm/s 1/2πm/s 1/πm/s Solution: The correct answer is 1/πm/s We know that the block's greatest speed occurs when it is in balance. Applying mechanical energy conservation at the equilibrium...

(A) small, positive and small, positive (B) large, positive and small, negative (C) small, positive and small, negative (D) large, negative and large, positive Solution: The correct answer is (C)...

√0.6 0.4 0.2 √0.2 Solution: The correct answer is

2ml2/3 4ml2/3 5ml2/3 ml2/12  Solution: The correct answer is  The inertia moments of rods AD and BC are as follows:  $ \frac{1}{3}m{{T}^{2}} $ Because rod AB is on the X-axis, its moment of inertia...

Solution: The correct answer is A.  

0.1m 0.2m 0.6m 0.8m Solution: The correct answer is  There are six loops in the fifth overtone, each of which is half wavelength long. $ 6\frac{\lambda }{2}=L=2.4\,m $ $ \lambda =0.8\,m $ Now,...

4 cm 8 cm 12 cm 16 cm Solution: the correct answer is B. 8cm We know, $ v=\frac{c}{\mu }\,\,where\,\,\mu =1.6 $ Let T1 represent the time it takes to travel from the source to the surface, and T2...

Solution: The correct answer is C. $ Time,\,\,T=\frac{1}{y} $ $ speed\,of\,proton,\,v=\frac{2\pi R}{T}=2\pi Ry $ $ For\text{ }circular\text{ }motion\text{ }in\text{ }the\text{ }dees- $ $...

(A) is one in which width of depletion layer increases (B) is one in which potenital barrier increases (C) acts as closed switch (D) acts as open switch Solution: The correct answer is (C) acts as...

3h 4h 2h h Solution: The correct answer is A. 3h $ h=\frac{2T\cos \theta }{r\rho g} $ $ \Rightarrow h\,\alpha \,\frac{1}{r} $ $ A=\pi {{r}^{2}},\,here\,\,r\,\alpha \,\sqrt{A} $ $ \therefore...

Solution; The correct answer is D. $ \frac{{{C}_{p}}}{{{C}_{v}}}=\gamma  $ $ {{C}_{p}}=\gamma {{C}_{v}} $ $ {{C}_{p}}-{{C}_{v}}=R $ $ \gamma {{C}_{v}}-{{C}_{v}}=R $ $ {{C}_{v}}=\frac{R}{\gamma -1}...

Solution: The correct answer is A. The resistance of a body is related to its length and material resistivity, and inversely proportional to its cross-sectional area. $ {{R}_{1}}=\rho...

1/3A 4/3A 5/3A 7/3A Solution; The correct answer is B. 4/3 A Suppose that there is no loss in power transmission: $ {{E}_{1}}{{I}_{1}}={{E}_{2}}{{I}_{2}} $ $...