Two long straight parallel wires are a distance $$d$$ part. They carry steady equal currents flowing out of the plane of the paper. The variation of magnetic field $B$ along the line $$x x^{\prime}$$ is given by
A cylindrical wire has a mass $$(0.3 \pm 0.003) \mathrm{g}$$, radius $$(0.5 \pm 0.005) \mathrm{mm}$$ and length $$(6 \pm 0.06) \mathrm{cm}$$. The maximum percentage error in the measurement of its density is
At a metro station, a girl walks up a stationary escalator in $$20 \mathrm{~s}$$. If she remains stationary on the escalator, then the escalator take her up in $$30 \mathrm{~s}$$. The time taken by her to walk up on the moving escalator will be
Rain is falling vertically with a speed of $$12 \mathrm{~ms}^{-1}$$. A woman rides a bicycles with a speed of $$12 \mathrm{~ms}^{-1}$$ in east to west direction. What is the direction in which she should hold her umbrella?