A body is projected from the ground at an angle of \(45^{\circ}\) with the horizontal. Its velocity after \(2s\) is \(20 \,ms ^{-1}\). The maximum height reached by the body during its motion is \(m\). (use \(g =10\, ms ^{-2}\) )

A potentiometer wire \(PQ\) of \(1\,m\) length is connected to a standard cell \(E _{1}\). Another cell \(E _{2}\) of emf \(1.02\, V\) is connected with a resistance \('r'\) and switch \(S\) (as shown in figure). With switch \(S\) open, the null position is obtained at a distance of \(49\, cm\) from \(Q\). The potential gradient in the potentiometer wire is.......\(V/cm\)

A capacitor of capacitance \(100\  \mu \mathrm{F}\) is charged to a potential of \(12  \mathrm{~V}\) and connected to a \(6.4 \ \mathrm{mH}\) inductor to produce oscillations. The maximum current in the circuit would be :

A bullet \(10\,g\) leaves the barrel of gun with a velocity of \(600\,m / s\). If the barrel of gun is \(50\,cm\) long and mass of gun is \(3\,kg\), then value of impulse supplied to the gun will be \(.....\,Ns\)

Given below are two statements: Statement \(I:\) Acceleration due to earth's gravity decreases as you go 'up' or 'down' from earth's surface. Statement \(II:\) Acceleration due to earth's gravity is same at a height ' \(h\) ' and depth ' \(d\) ' from earth's surface, if \(h = d\). In the light of above statements, choose the most appropriate answer form the options given below

The density and breaking stress of a wire are \(6 \times\) \(10^4 \mathrm{~kg} / \mathrm{m}^3\) and \(1.2 \times 10^8 \mathrm{~N} / \mathrm{m}^2\) respectively. The wire is suspended from a rigid support on a planet where acceleration due to gravity is \(\frac{1^{\text {rd }}}{3}\) of the value on the surface of earth. The maximum length of the wire with breaking is _______ \(\mathrm{m}\) (take, \(\mathrm{g}=\) \(\left.10 \mathrm{~m} / \mathrm{s}^2\right)\)

Unpolarized light of intensity \(I_0\) incident on surface of a block of glass at Brewster's angle. In that case, which one of ihe following statements is true ?

If the r.m.s. speed of chlorine molecule is \(490\,m / s\) at \(27^{\circ}\,C\), the r.m.s. speed of argon molecules at the same temperature will be \(......\,m/s\) (Atomic mass of argon \(=39.9\,u\), molecular mass of chlorine \(=70.9\,u )\)

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Net dipole moment of a polar linear isotropic dielectric substance is not zero even in the absence of an external electric field.
Reason (R) : In absence of an external electric field, the different permanent dipoles of a polar dielectric substance are oriented in random directions.
In the light of the above statements, choose the most appropriate answer from the options given below :

A square loop \(\mathrm{PQRS}\) having \(10\) turns, area \(3.6 \times\) \(10^{-3} \mathrm{~m}^2\) and resistance \(100 \Omega\) is slowly and uniformly being pulled out of a uniform magnetic field of magnitude \(\mathrm{B}=0.5 \mathrm{~T}\) as shown. Work done in pulling the loop out of the field in \(1.0 \mathrm{~s}\) is _______ \(\times 10^{-6} \mathrm{~J}\).

A string is wound around a hollow cylinder of mass \(5\, kg\) and radius \(0.5\,m\). If the string is now pulled with a horizontal force of \(40\, N\), and the cylinder is rolling without slipping on a horizontal surface (see figure), then the angular acceleration of the cylinder will be ......... \(rad/s^2\) .(Neglect the mass and thickness of the string)

In the circuit, the logical value of \(A =1\) or \(B =1\) when potential at \(A\) or \(B\) is \(5\,V\) and the logical value of \(A=0\) or \(B=0\) when potential at \(A\) or \(B\) is \(0\,V\). The truth table of the given circuit will be :

Two sources of light emit X-rays of wavelength \(1\, nm\) and visible light of wavelength \(500\, nm ,\) respectively. Both the sources emit light of the same power \(200\, W\). The ratio of the number density of photons of X-rays to the number densitty of photons of the visible light of the given wavelengths is