Neet PYQ 2007

In the energy band diagram of a material shown below, the open circles and filled circles denote holes and electrons respectively. The material is a/an:

A car moves from $X$ to $Y$ with a uniform speed $v_u$ and returns to $X$ with a uniform speed $v_d$. The average speed for this round trip is:

A particle executes simple harmonic oscillation with an amplitude $a$. The period of oscillation is $T$. The minimum time taken by the particle to travel half of the amplitude from the equilibrium position is:

A $5\text{W}$ source emits monochromatic light of wavelength $5000\text{A˚}$. When placed $0.5\text{m}$ away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of $1.0\text{m}$, the number of photoelectrons liberated, will be reduced by a factor of:

A block $B$ is pushed momentarily along a horizontal surface with an initial velocity $v$. If $\mu$ is the coefficient of sliding friction between $B$ and the surface, block $B$ will come to rest after a time: