For the following questions answer them individually
A wire of resistance $$R$$ and length $$L$$ is cut into $$5$$ equal parts. If these parts are joined parallely, then resultant resistance will be :
A wire of length $$10$$ cm and radius $$\sqrt{7} \times 10^{-4}$$ m connected across the right gap of a meter bridge. When a resistance of $$4.5 \; \Omega$$ is connected on the left gap by using a resistance box, the balance length is found to be at $$60$$ cm from the left end. If the resistivity of the wire is $$R \times 10^{-7} \; \Omega$$ m, then value of $$R$$ is :
A proton moving with a constant velocity passes through a region of space without any change in its velocity. If $$\vec{E}$$ and $$\vec{B}$$ represent the electric and magnetic fields respectively, then the region of space may have :Â
(A) $$E = 0, B = 0$$; (B) $$E = 0, B \neq 0$$; (C) $$E \neq 0, B = 0$$; (D) $$E \neq 0, B \neq 0$$. Choose the most appropriate answer from the options given below :
A rectangular loop of length $$2.5$$ m and width $$2$$ m is placed at $$60°$$ to a magnetic field of $$4$$ T. The loop is removed from the field in $$10$$ sec. The average emf induced in the loop during this time is
A plane electromagnetic wave propagating in $$x$$-direction is described by $$E_y = (200 \text{ V m}^{-1}) \sin[1.5 \times 10^7 t - 0.05x]$$. The intensity of the wave is : (Use $$\epsilon_0 = 8.85 \times 10^{-12} \text{ C}^2 \text{ N}^{-1} \text{ m}^{-2}$$)
If the refractive index of the material of a prism is $$\cot\left(\frac{A}{2}\right)$$, where $$A$$ is the angle of prism then the angle of minimum deviation will be
A convex lens of focal length $$40$$ cm forms an image of an extended source of light on a photoelectric cell. A current $$I$$ is produced. The lens is replaced by another convex lens having the same diameter but focal length $$20$$ cm. The photoelectric current now is
The radius of third stationary orbit of electron for Bohr's atom is $$R$$. The radius of fourth stationary orbit will be:
Which of the following circuits is reverse-biased?
Identify the physical quantity that cannot be measured using spherometer :
