The \(I-V\) characteristics of an electronic device shown in the figure. The device is _______.

Sand is being dropped from a stationary dropper at a rate of \(0.5\,kgs ^{-1}\) on a conveyor belt moving with a velocity of \(5\,ms ^{-1}\). The 10.Power needed to keep belt moving with the same velocity will be.

A ball of mass \(200\,g\) rests on a vertical post of height \(20\,m\). A bullet of mass \(10\,g\), travelling in horizontal direction, hits the centre of the ball. After collision both travels independently. The ball hits the ground at a distance \(30\,m\) and the bullet at a distance of \(120\,m\) from the foot of the post. The value of initial velocity of the bullet will be \(............m/s\) (if \(\left.g =10 m / s ^2\right)\)

A bullet of \('4\,g'\) mass is fired from a gun of mass \(4 \,{kg}\). If the bullet moves with the muzzle speed of \(50\, {ms}^{-1}\), the impulse imparted to the gun and velocity of recoil of gun are :

A liquid column of height \(0.04 \mathrm{~cm}\) balances excess pressure of soap bubble of certain radius. If density of liquid is \(8 \times 10^3 \mathrm{~kg} \mathrm{~m}^{-3}\) and surface tension of soap solution is \(0.28 \mathrm{Nm}^{-1}\), then diameter of the soap bubble is _______ \(\mathrm{cm}\). \(\text { (if } g=10 \mathrm{~ms}^{-2} \text { ) }\)

In \(Li^{++},\) electron in first Bohr orbit is excited to a level by a radiation of wavelength \(\lambda .\) When the ion gets deexcited to the ground state in all possible ways(including intermediate emission) a total of six spectral lines are observed. What is the value of \(\lambda \)?.....\(nm\) (Given: \(h = 6.63\times 10^{34}\,js; e = 3 \times 10^8\,ms^{-1}\) )

When an object is placed 40 cm away from a spherical mirror an image of magnification \(\frac{1}{2}\) is produced. To obtain an image with magnification of \(\frac{1}{3}\), the object is to be moved :

A point like object is placed at a distance of \(1\, m\) in front of a convex lens of focal length \(0.5\, m .\) A plane mirror is placed at a distance of \(2\,m\) behind the lens. The position and nature of the final image formed by the system is 

A plane electromagnetic wave is moving in free space with velocity \(c =3 \times 10^8 m / s\) and its electric field is given as \(\overrightarrow{ E }=54 \sin ( kz -\omega t ) \hat{ j } V / m\), where \(\hat{j}\) is the unit vector along \(y\)-axis. The magnetic field vector \(\overrightarrow{ B }\) of the wave is :