Download App

Current Electricity — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsCurrent Electricity1 Mark
MCQ
Assertion : The drift velocity of electrons in a metallic wire will decrease, if the temperature of the wire is increased.
Reason : On increasing temperature, conductivity of metallic wire decreases.
  • A
    If both assertion and reason are true and the reason is the correct explanation of the assertion.
  • ✓
    If both assertion and reason are true but reason is not the correct explanation of the assertion.
  • C
    If assertion is true but reason is false.
  • D
    If the assertion and reason both are false.
✓

Answer

Correct option: B.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
 If both assertion and reason are true but reason is not the correct explanation of the assertion.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from Current Electricity→Current Electricity — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

If in a voltaic cell 5 gm of zinc is consumed, then we get how many ampere hours ? (Given that E.C.E. of Zn is $3.387 \times 10^{-7}$ kg/coulomb)
→
The coefficient of self induction of a coil is given by.
→
On interchanging the resistances, the balance point of a meter bridge shifts to the left by $10\ cm$. The resistance of their series combination is $1\ k\Omega$. How much was the resistance on the left slot before interchanging the resistances?  ..................  $\Omega$
→
A thin spherical conducting shell of radius $R$ has a charge $q$. Another charge $Q$ is placed at the centre of the shell. The electrostatic potential at a point $p$ at distance $\frac{R}{2}$ from the centre of the shell is
→
An inductor of inductance $2\,mH$ is connected to a $220\,V , 50\,Hz$ $a.c.$ source. Let the inductive reactance in the circuit is $X _1$. If a $220\,V$ dc source replaces the ac source in the circuit, then the inductive reactance in the circuit is $X _2 . X _1$ and $X _2$ respectively are
→
$A$ thin prism of angle $5^o$ is placed at a distance of $10\,cm$ from object. What is the distance of the image from object? (Given $\mu$ of prism $= 1.5$)
→
Find the peak current and reZsonant frequency of the following circuit (as shown in figure).
→
Assertion : In the given circuit if lamp B or C fuses then light emitted by lamp A decreases.







Reason : Voltage on A decreases. 
→
A microscope has an objective of focal length $1.5\, cm$ and an eye-piece of focal length $2.5\, cm$. If the distance between objective and eye-piece is $25\, cm$ the approximate value of magnification produced for relaxed eye is ?
→
The current sensitivity of a galvanometer can be increased by:

$(A)$ decreasing the number of turns

$(B)$ increasing the magnetic field

$(C)$ decreasing the area of the coil

$(D)$ decreasing the torsional constant of the spring

Choose the most appropriate answer from the options given below.

→