Question

14. An RC circuit is built up of a resistance of 10 Mega Ohms and a capacitance of 100 nano Farad connected to a 6-V battery. What is the charge on the capacitor after 2 time constants?

a) none

b) 5.18E-7 C

c) 0.6E-6 C

d) 0.6E-6 C

e) 4.41E-6 C

15. A far-sighted person can see objects distinctly far out needs a concave lens for eye correction and a near-sighted person needs a convex lens to correct the eye problem:

a) true

b) false

16. The material of a wire of 500 cm length and 2 mm diameter has a resistivity of 5E-8 Ohm.m. The resistance of the wire is:

a) none

b) about 0.08 Ohm

c) 7.96E-6 Ohm

d) about 0.08 Ohm.cm

e) 12.5E-6 Ohm

17. If a coil of wire of N turns, each of area A, rotates with a constant angular speed w(=2πf) in a uniform magnetic field, the induced emf is:

a) proportional to N, B, A, and f

b) none

c) proportional to B

d) proportional to F

e) proportional to N

f) proportional to A

Please provide an explanation.

Answer 1