Question
Define the term resistivity and write the SI unit.
✓
Answer
The resistivity of a material of a conductor is defined as the resistance offered by a conductor of length 1 m and area of cross-section $1 \mathrm{~m}^2$. Its SI unit is ohm $\times$ metre $(\Omega \mathrm{m})$.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
What is a capacitive and an inductive AC circuit? Explain.
Why cannot longitudinal waves be polarized?
Two capacitors of equal capacitance are connected to a battery as shown. Switch $S$ is initially in closed state. Now the switch $S$ is opened and a material of dielectric constant $\epsilon_r=3$ is filled between the plates of the capacitor. Find the ratio of the values of electrical energy stored in the capacitors before and after placing the dielectric material. 
→When n capacitors of capacitance C are connected in series, the equivalence is $C _s$ and when connected in parallel, the equivalence is $C _p$. Prove that $C _{ P }- C _{ S }=\frac{\left(n^2-1\right) C }{n}$
→Draw a circuit diagram of n-p-n transistor amplifier in CE configuration. Under what condition does the transistor act as an amplifier?
Write Maxwell's equations.
An electron enters with a velocity $v = v_0i$ into a cubical region (faces parallel to coordinate planes) in which there are uniform electric and magnetic fields. The orbit of the electron is found to spiral down inside the cube in plane parallel to the x-y plane. Suggest a configuration of fields E and B that can lead to it.
→The oscillating magnetic field in a plane electromagnetic wave is given by$\text{B}_{y} = ( 8 \times 10^{-6}) sin [2\times 10 ^{11}t + 300 \pi\text{x}] T$.
→- Calculate the wavelength of the electromagnetic wave.
- Write down the expression for the oscillating electric field.
Find the neutral temperature and inversion temperature of a copper-iron thermocouple if the reference junction is kept at $0^\circ$C. Use the data in the table.
|
|||||||||||||||||||||||||||
|
Ultraviolet radiations of different frequencies $v_1$ and $v_2$, are incident on two photosensitive materials having work functions $W_1$ and $W_2\left(W_1>W_2\right)$ respectively. The kinetic energy of the emitted photoelectrons is same in both the cases. Which one of the two relations will be of the higher frequency?
→