Electricity and current Quiz 1

Question 1

Smitha connected a wire with a current source for a time mentioned to be $$1\,min$$. If a total of $$4\,A$$ flows through the circuit, then what will be the number of charge carriers in it?

Accepted Answer

$$1.5	imes {{10}^{21}}$$

Answer

$$150	imes {{10}^{21}}$$

Answer

$$4.3	imes {{10}^{21}}$$

Answer

$$5.8	imes {{10}^{21}}$$

Question 2

The random thermal velocities of an electron has been mentioned as $$	ext{5 }m{{s}^{-1}},8	ext{ }m{{s}^{-1}},7	ext{ }m{{s}^{-1}},-5	ext{ }m{{s}^{-1}}and-3	ext{ }m{{s}^{-1}}$$. The average thermal velocity has been given as$$2.4	ext{ }m{{s}^{-1}}$$. Calculate the number of free electrons in this?

Accepted Answer

$$5$$

Answer

$$8$$

Answer

$$10$$

Answer

$$1$$

Question 3

Hina once applied an electric field of value mentioned as $$5	ext{ }V{{m}^{-1}}$$ in the negative $$x$$ direction. Calculate the force applied by this electric field.

Accepted Answer

$$8	imes {{10}^{-19}}	ext{ }N$$, negative $$x$$ direction

Answer

$$1.6	imes {{10}^{-19}}	ext{ }N$$, positive $$x$$ direction

Answer

$$8	imes {{10}^{-19}}	ext{ }N$$, positive $$x$$ direction

Answer

$$1.6	imes {{10}^{-19}}	ext{ }N$$,negative $$x$$ direction

Question 4

A metal of atomic number $$8$$ and atomic weight $$1.22	ext{ }gc{{m}^{-3}}$$ is having  $$5.8	imes {{10}^{-19}}$$free electrons in it. Calculate the density of the metal atom if the free electron density be $$3.2	imes {{10}^{-19}}	ext{ }gc{{m}^{-3}}$$.

Accepted Answer

$$1.12	imes {{10}^{-22}}	ext{ }gc{{m}^{-3}}$$

Answer

$$3.4	imes {{10}^{-22}}	ext{ }gc{{m}^{-3}}$$

Answer

$$6	imes {{10}^{-22}}	ext{ }gc{{m}^{-3}}$$

Answer

$$4.7	imes {{10}^{-22}}	ext{ }gc{{m}^{-3}}$$

Question 5

Somu is having a wire of resistance $$55	ext{ }\Omega $$, which is having the length of the wire be $$4	ext{ }m$$ and the area of cross section be $$8	ext{ }{{m}^{2}}$$. What will be the conductivity of the wire?

Accepted Answer

$$0.009	ext{ }siemens\,{{m}^{-1}}$$

Answer

$$0.005	ext{ }siemens\,{{m}^{-1}}$$

Answer

$$9	ext{ }siemens\,{{m}^{-1}}$$

Answer

$$0.01	ext{ }siemens\,{{m}^{-1}}$$