An electric dipole with dipole moment $5\times10^{-6}Cm$ is aligned with the direction of a uniform electric field of magnitude $4\times10^{5}N/C$. The dipole is then rotated through an angle of $60^{\circ}$ with respect to the electric field. The change in the potential energy of the dipole is:
There are two inclined surfaces of equal length (L) and same angle of inclination $45^{\circ}$ with the horizontal. One of them is rough and the other is perfectly smooth. A given body takes 2 times as much time to slide down on rough surface than on the smooth surface. The coefficient of kinetic friction $(\mu_{k})$ … Read more
The plates of a parallel plate capacitor are separated by d. Two slabs of different dielectric constant $K_{1}$ and $K_{2}$ with thickness $\frac{3}{8}d$ and $\frac{d}{2}$ respectively are inserted in the capacitor. Due to this, the capacitance becomes two times larger than when there is nothing between the plates. If $K_{1}=1.25~K_{2}$, the value of $K_{1}$ is:
A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is:
The kinetic energies of two similar cars A and B are 100 J and 225 J respectively. On applying breaks, car A stops after 1000 m and car B stops after 1500 m. If $F_{A}$ and $F_{B}$ are the forces applied by the breaks on cars A and B respectively, then the ratio of $\frac{F_{A}}{F_{B}}$ … Read more
Two cities X and Y are connected by a regular bus service with a bus leaving in either direction every T min. A girl is driving scooty with a speed of $60~km/h$ in the direction X to Y notices that a bus goes past her every 30 minutes in the direction of her motion, and … Read more
A photon and an electron (mass m) have the same energy E. The ratio $(\lambda_{photon}/\lambda_{electron})$ of their de Broglie wavelengths is: (c is the speed of light)
The current passing through the battery in the given circuit, is:
A uniform rod of mass 20 kg and length 5 m leans against a smooth vertical wall making an angle of $60^{\circ}$ with it. The other end rests on a rough horizontal floor. The friction force that the floor exerts on the rod is (Take $g=10~m/s^{2}$)
Which of the following options represent the variation of photoelectric current with property of light shown on the x-axis?