MCQ 11 Mark
The expression for the magnetic energy per unit volume stored in a solenoid in terms of magnetic field is ___________ .
AnswerCorrect option: A. $\frac{1}{2} \frac{B^2}{\mu_0}$
View full question & answer→MCQ 21 Mark
Following figure shows planar loops of different shapes moving out of or into a region of a magnetic field which is directed normal to the plane of the loop away from the reader. The direction of induced current is in anticlockwise ___________ .
- A
in the loops (ii) and (iii)
- B
- C
- ✓
View full question & answer→MCQ 31 Mark
A wheel with 10 metallic spokes each 0.5 m long is rotated with a speed of $120 rev / min$ in a plane normal to the horizontal component of earth's magnetic field $H _{ E }$ at a place. If $H _{ E }=0.4 G$ at the place, then induced $emf =$ ___________ $\left(1 G =10^{-4} T\right)$
- A
$6.28 \times 10^{-5} \mu V$
- B
$6.28 \times 10^{-2} \mu V$
- ✓
$6.28 \times 10^{-2} m V$
- D
$6.28 \times 10^{-5} m V$
AnswerCorrect option: C. $6.28 \times 10^{-2} m V$
View full question & answer→MCQ 41 Mark
Dimensional formula of self-inductance is ___________ .
AnswerCorrect option: D. $M ^1 L^2 T^{-2} A^{-2}$
View full question & answer→MCQ 51 Mark
The phenomenon of perfect diamagnetism in super conductors is called the ___________ .
MCQ 61 Mark
Magnetic needle of a magnetic compass is made up of ___________ .
MCQ 71 Mark
A closely wound solenoid of 1000 turns and area of cross-section $2 \times 10^{-4} m_2$ and carrying a current of 5.0 A , then magnetic moment is ___________ $Am ^2$
View full question & answer→MCQ 81 Mark
Two very long straight, parallel conductors of negligible cross-section carrying equal electric current are placed one metre apart in vacuum would produce a force equal to ___________ N per metre length. ( $\mu_0=4 \pi \times 10^{-7} TmA ^{-1}$ )
- A
$2 \times 10^{-4}$
- B
$2 \times 10^{-10}$
- ✓
$2 \times 10^{-13}$
- D
$2 \times 10^{-7}$
AnswerCorrect option: C. $2 \times 10^{-13}$
View full question & answer→MCQ 91 Mark
A circular coil of 200 turns, each of radius 8.0 cm carries a current of 0.40 A , then intensity of magnetic field at the centre of the coil is ___________ -.
- A
$\pi \times 10^{-6}$
- B
$\pi \times 10^{-4}$
- C
$2 \pi \times 10^{-6}$
- ✓
$2 \pi \times 10^{-4}$
AnswerCorrect option: D. $2 \pi \times 10^{-4}$
View full question & answer→MCQ 101 Mark
The power wasted in the connecting wires of voltage V and finite resistance $R _{ c }$ from the power station to the device of power $P$ is ___________ -.
AnswerCorrect option: B. $\frac{P^2 R_c}{V^2}$
View full question & answer→MCQ 111 Mark
If there are 3 parallely connected cells of emf $\varepsilon_1=1.2 V, \varepsilon_2=1.4 V, \varepsilon_3=1.5 V$ and of internal resistances $r_1=0.1 \Omega, r_2=0.2 \Omega$ and $r_3=0.3 \Omega$, then find $\frac{\varepsilon_{e q}}{r_{e q}}=$ ___________ $V \Omega^{-1}$.
View full question & answer→MCQ 121 Mark
A neligibly small current is passed through a wire of length 15 m and uniform cross-section $6 \times 10^{-7} m^2$ and its resistance is measured to be $5 \Omega$, then resistivity of material at temperature of experiment is, ___________ $\Omega m$.
- A
$3 \times 10^7$
- B
$3 \times 10^{-7}$
- ✓
$2 \times 10^{-7}$
- D
$2 \times 10^7$
AnswerCorrect option: C. $2 \times 10^{-7}$
View full question & answer→MCQ 131 Mark
For the given circuit, $V _{ A }- V _{ C }=$ ___________ V.
View full question & answer→MCQ 141 Mark
For parallel capacitor having plates with finite area, the electric field lines bend outward at the edges. This effect is called ___________ .
MCQ 151 Mark
A 12 pF capacitor is connected to a 50 V battery. Then electrostatic energy stored in the capacitor will be ___________ J.
- A
$2.5 \times 10^{-10}$
- B
$1.5 \times 10^{-10}$
- C
$2.5 \times 10^{-8}$
- ✓
$1.5 \times 10^{-8}$
AnswerCorrect option: D. $1.5 \times 10^{-8}$
View full question & answer→MCQ 161 Mark
A regular hexagon of side 9 cm has a charge 5 $\mu C$ at each of its vertices, then electric potential at its centre is ___________ V.
\[\left(k=9 \times 10^9 Nm^2 C^{-2}\right)\]
- A
$3 \times 10^8$
- B
$3 \times 10^5$
- ✓
$3 \times 10^6$
- D
$3 \times 10^7$
AnswerCorrect option: C. $3 \times 10^6$
View full question & answer→MCQ 171 Mark
When dipole moment $\vec{p}$ is parallel to nonuniform electric field $\vec{E}$, Net force on electric dipole is ___________ .
AnswerCorrect option: A. in the direction of increasing field
View full question & answer→MCQ 181 Mark
If a body contains $10^{24}$ electrons and $10^{26}$ protons, the total amount of charge on the body is ___________ C.
- A
$1.58 \times 10^{-7}$
- ✓
$1.58 \times 10^7$
- C
$1.6 \times 10^{17}$
- D
$1.6 \times 10^{-17}$
AnswerCorrect option: B. $1.58 \times 10^7$
View full question & answer→MCQ 191 Mark
An infinite linear charge produces a field of $9 \times 10^4 NC ^{-1}$ at a distance of 2 cm then linear charge density is ___________ .
- A
$0.2 \mu Cm ^{-1}$
- B
$0.2 m Cm ^{-1}$
- ✓
$0.1 \mu Cm ^{-1}$
- D
$0.1 m Cm ^{-1}$
AnswerCorrect option: C. $0.1 \mu Cm ^{-1}$
View full question & answer→MCQ 201 Mark
If electric flux through cubic Gaussioan surface is $1.9 \times 10^5 Nm ^2 C ^{-1}$ then electric charge at its centre is ___________ . (Edge length of cube $=9.0 cm$ )
AnswerCorrect option: D. $2 \mu C$
View full question & answer→MCQ 211 Mark
Which one of the following is inorganic compound semiconductor?
MCQ 221 Mark
In an $n$-type silicon, which of the following statement is true?
- ✓
Holes are minority carriers and pentavalent atoms are the dopants
- B
Electrons are minority carriers and pentavalent atoms are the dopants
- C
Holes are majority carriers and trivalent atoms are dopants
- D
Electrons are majority carriers and trivalent atoms are the dopants.
AnswerCorrect option: A. Holes are minority carriers and pentavalent atoms are the dopants
View full question & answer→MCQ 231 Mark
Carbon, silicon and germanium have four valence electrons each. These are characterised by valence and conduction bands separated by energy band gap, respectively, equal to $\left(E_R\right)_C,\left(E_R\right)_{s i}$ and $\left( E _{ g }\right)_{ Gc ^*}$. Which of the following statement is true?
- A
$\left( E _g\right)_{ C }<\left( E _g\right)_{ Si }<\left( E _g\right)_{ Gc }$
- B
$\left( E _g\right)_{ C }<\left( E _g\right)_{ Gc }>\left( E _g\right)_{ Si }$
- ✓
$\left( E _g\right)_{ C }>\left( E _g\right)_{ Si }>\left( E _g\right)_{ Gc }$
- D
$\left( E _g\right)_{ Si }<\left( E _{ g }\right)_{ Gc }<\left( E _{ g }\right)_{ C }$
AnswerCorrect option: C. $\left( E _g\right)_{ C }>\left( E _g\right)_{ Si }>\left( E _g\right)_{ Gc }$
View full question & answer→MCQ 241 Mark
If an unbiased $p-n$ junction, the holes diffuse from the $p$ - region to $n$ - region because
- A
holes in the $p$-region repel them
- B
they move across the junction by the potential difference
- ✓
holes concentration in $p$ - region is more as compared to $n$ - region
- D
free electrons in the $n$-region attract them
AnswerCorrect option: C. holes concentration in $p$ - region is more as compared to $n$ - region
View full question & answer→MCQ 251 Mark
Density of nucleus is ___________ the atomic mass number of atom.
- ✓
- B
directly proportional to the square of
- C
inversely proportional to
- D
View full question & answer→MCQ 261 Mark
Complete the following nuclear reaction. \[{ }_0^1 n+{ }_{92}^{235} U-{ }_{92}^{236} U---+{ }_{41}^{99} Nb+--\]
- A
${ }_{51}^{130} Sb ; 2{ }_0^1 n$
- ✓
${ }_{51}^{133} Sb ; 4{ }_0^1 n$
- C
${ }_{54}^{140} Xe ; 2{ }_0^1 n$
- D
${ }_{56}^{144} Ba ; 3{ }_0^1 n$
AnswerCorrect option: B. ${ }_{51}^{133} Sb ; 4{ }_0^1 n$
View full question & answer→MCQ 271 Mark
The ratio of the nuclear radii of the gold isotope ${ }_{79}^{197} Au$ and the silver isotope ${ }_{47}^{107} Ag$ is ___________ .
View full question & answer→MCQ 281 Mark
${ }_{92}^{238} U$ and ${ }_{90}^{236} Th$ are ___________ of each other.
View full question & answer→MCQ 291 Mark
In the experiment of $\alpha$ - scattering for the head on collision angle of scatterig $\theta=$ ___________ .
- ✓
$180^{\circ}$
- B
$60^{\circ}$
- C
$90^{\circ}$
- D
$0^{\circ}$
AnswerCorrect option: A. $180^{\circ}$
View full question & answer→MCQ 301 Mark
The ground state energy of hydrogen atom is -13.6 eV then in this state potential energy =______ Ev.
MCQ 311 Mark
The radius of the innermost electron orbit of a hydrogen atom is $5.3 \times 10^{-11}$ then radius for $n=2$ is ___________ $m$.
- A
$4.12 \times 10^{-10}$
- B
$3.12 \times 10^{-10}$
- ✓
$2.12 \times 10^{-10}$
- D
$1.22 \times 10^{-10}$
AnswerCorrect option: C. $2.12 \times 10^{-10}$
View full question & answer→MCQ 321 Mark
Which two physical quantities have same units?
- A
Work function and threshold frequency
- ✓
Planck's constant and angular momentum
- C
Work function and stopping potential
- D
Planck's constant and angular velocity
AnswerCorrect option: B. Planck's constant and angular momentum
View full question & answer→MCQ 331 Mark
Momentum of photon of frequency $v$ is ___________ .
- ✓
$\frac{h v}{c}$
- B
$\frac{h c}{v}$
- C
$\frac{c}{h v}$
- D
$h c v$
AnswerCorrect option: A. $\frac{h v}{c}$
View full question & answer→MCQ 341 Mark
Wavelength of an electromagnetic radiation is $\lambda_1$ and its de Broglie wavelength of its quantum is $\lambda_2$ then ___________ .
AnswerCorrect option: D. $\lambda_1=\lambda_2$
View full question & answer→MCQ 351 Mark
In an experiment of photoelectric effect, the slope of graph of cut-off voltage versus freqency is ___________ Vs.$\left( h =6.625 \times 10^{-34} Js \right)$
- A
$2.14 \times 10^{-15}$
- B
$6.14 \times 10^{-15}$
- ✓
$4.14 \times 10^{-15}$
- D
$1.41 \times 10^{-15}$
AnswerCorrect option: C. $4.14 \times 10^{-15}$
View full question & answer→MCQ 361 Mark
The photoelectric cut-off voltage in a certain experiment is 4 V , then maximum kinetic energy of emitted photoelectrons is ___________ eV.
MCQ 371 Mark
According to Huygens' argument, the amplitude of the secondary wavelets is ___________ in the forward direction and ___________ in the backward direction.
MCQ 381 Mark
In the case of diffraction due to a single slit, the width of the slit is half of the wavelength of incident light. The angle of diffraction $\theta$ for the second order minimum formed in the diffraction pattern on the screen is ___________ .
- A
$8^{\circ}$
- B
$5^{\circ}$
- C
$6^{\circ}$
- ✓
$4^{\circ}$
AnswerCorrect option: D. $4^{\circ}$
View full question & answer→MCQ 391 Mark
When a plane wavefront is incident on a thin conver lens, the emerging wavefront becomes ___________
- A
appropriate choice is not given
- B
- ✓
- D
View full question & answer→MCQ 401 Mark
If a Prism is to be used to invert image without changing the size, the critical angle fot the material of the Prism ___________ .
- ✓
$i_c<\frac{\pi}{4} rad$
- B
$i_c>\frac{\pi}{4} rad$
- C
$i_c=\frac{\pi}{2} rad$
- D
$i_c=\frac{\pi}{3} rad$
AnswerCorrect option: A. $i_c<\frac{\pi}{4} rad$
View full question & answer→MCQ 411 Mark
Double lenses are to be manufactured from glass of refractive index 1.5 , with both faces of the same radius of curvature R. If focal length is $f$ then ___________ .
- A
$R =\frac{f}{4}$
- ✓
$R =f$
- C
$R =\frac{f}{2}$
- D
$R =2 f$
AnswerCorrect option: B. $R =f$
View full question & answer→MCQ 421 Mark
A square of size $1 mm^2$ is being viewed through a magnifying glass, the image of the square has an area of $6.25 mm^2$. The magnification produced by the lens is ___________ .
View full question & answer→MCQ 431 Mark
For compound microscope, image distance of objective is $v_0$ and object distance of eye piece is $u_e$ then distance between its two lenses is ___________ .
- A
$\frac{\left|u_e\right|}{v_0}$
- B
$\frac{\left|v_0\right|}{u_e}$
- C
$\left|v_0\right|-\left|u_e\right|$
- ✓
$\left|v_0\right|+\left|u_e\right|$
AnswerCorrect option: D. $\left|v_0\right|+\left|u_e\right|$
View full question & answer→MCQ 441 Mark
A charged particle oscillates about its mean equilibrium position with a frequency of $10^9 Hz$, then frequency of electromagnetic wave is ___________ Hz .
AnswerCorrect option: A. $10^9$
View full question & answer→MCQ 451 Mark
___________ radiations are used in LASIK eye surgery.
MCQ 461 Mark
A charged $30 \mu F$ capacitor is connected to a 27 mH inductor then frequency is ___________ Hz .
View full question & answer→MCQ 471 Mark
A $15.0 \mu F$ capacitor is connected to a $220 V, 50$ Hz source, then the capacitive reactance is ___________ $\Omega$.
View full question & answer→MCQ 481 Mark
In LCR circuit, power is dissipated ___________ circuit.
- A
in all resistor, capacitor and inductor
- B
- C
- ✓
View full question & answer→MCQ 491 Mark
A $60 \mu F$ capacitor is connected to a $110 V, 60 Hz$ ac supply. rms value of current is ___________ A.
View full question & answer→MCQ 501 Mark
Current in a circuit falls from 5.0 A to 0.0 A in 0.1 s . If an average emf of 200 V induced then selfinductance of circuit is ___________ H.