MCQ Questions for Class 12 Medical Physics Current Electricity Quiz 14

Current in a resistor

$R$ uniformly decreases from som value to zero in time

$\Delta t$ . Total change, that crosses the cross section is

$q$ . Choose the correct option(s)

0%
Heat generated in the resistance during this process is $\cfrac{4}{3}\cfrac{{q}^{2}R}{\Delta t}$
0%
Heat generated in the resistance during this process is $\cfrac{2}{3}\cfrac{{q}^{2}R}{\Delta t}$
0%
maximum current is ${i}_{0}=\cfrac{2q}{\Delta t}$
0%
maximum current is ${i}_{0}=\cfrac{q}{\Delta t}$

A battery of e.m.f. E and internal resistance r is connected to an external resistance R the condition for maximum power transfer is

0%
r < R
0%
r > R
0%
r = $\dfrac{1}{R}$
0%
r = R

In a practical Wheatstone bridge circuit (Fig.), when one more resistance of

$100 \Omega$ is connected in parallel with unknown resistance

$x$ , then the ratio

$l_{1} / l_{2}$ becomes

$2 . l$ , is the balance length.

$A B$ is a uniform wire. Then the value of

$x$ must be

0%
$50 \Omega$
0%
$100 \Omega$
0%
$200 \Omega$
0%
$400 \Omega$

A silver and copper voltameters are connected in parallel to a

$12$ V battery of negligible resistance. At what rate is energy being delivered by the battery, if in

$30$ minutes,

$1$ g of silver and

$1.8$ g of copper are deposited?(Assume electrochemical equivalent of silver

$=11.2\times 10^{-7}$ kg/C, electrochemical equivalent of copper

$=6.6\times 10^{-7}$ kg/C)

0%
$42.2$ J/s
0%
$40.4$ J/s
0%
$24.1$ J/s
0%
$20.4$ J/s

What amount of charge will flow through the battery?

0%
$20\mu C$
0%
$60\mu C$
0%
$40\mu C$
0%
No charge will flow

A lamp having tungsten filament consumes

$50$ W. Assume the temperature coefficient of resistance for tungsten is

$4.5\times 10^{-3}/^oC$ and the room temperature is

$20^o$ C. If the lamp burns, the temperature of its filament becomes

$2500^oC$ , then the power consumed at the moment switch is on, is?

0%
$608$ W
0%
$710$ W
0%
$215$ W
0%
$580$ W

In a series circuit, the current is different in each resistor.

0%
True
0%
False

In the given circuit, with steady current, the potential drop across the capacitor must be

0%
$V$
0%
$\dfrac{V}{2}$
0%
$\dfrac{V}{3}$
0%
$\dfrac{2 V}{3}$

The velocity of the particle when it crosses the x-axis is

0%
$20 \times 10^{-3} ms^{-1}$
0%
$40 \times 10^{-3} ms^{-1}$
0%
$30 \times 10^{-3} ms^{-1}$
0%
$50 \times 10^{-3} ms^{-1 }$

In a meter bridge, the point D is a neutral point (Fig 3.3).

0%
The meter bridge can have no other neutral point for this set of resistances.
0%
When the jockey contacts a point on meter wire left of D, current flows to B from the
wire.
0%
When the jockey contacts a point on the meter wire to the right of D, current flows from B
to the wire through the galvanometer.
0%
When R is increased, the neutral point shifts to left.

The three resistance of equal value are arranged in the different combinations shown below. Arrange them in increasing order of power dissipation

0%
III < II < IV < I
0%
II < III < IV < I
0%
I < IV < III < II
0%
I < III < II < IV

A current-carrying ohmic metal wire has a cross-sectional area that gradually becomes smaller from
one end of the wire to the other. The current has the same value for each section of the wire, so charge does not accumulate at any one point. How does the drift speed vary along the wire as the area becomes smaller?

0%
It increases
0%
It decreases
0%
It remains constant
0%
none of these

The current-versus-voltage behavior of a certain electrical device is shown in the figure. When the potential difference across the device is

$2\ V$ , what is its resistance?

0%
$1\ \Omega$
0%
$\dfrac{3}{4}\ \Omega$
0%
$\dfrac{3}{5}\ \Omega$
0%
Undefined
0%
None of these

Explanation

$R=V/I=2V/2A=1\Omega$

Instead of metal wires, a jute string can be used to make a circuit.

0%
True
0%
False

When resistors with different resistances are connected in parallel, which of the following must be the same for each resistor? Choose the correct answer.

0%
potential difference
0%
current
0%
power delivered
0%
charge entering each resistor in a given time interval
0%
none of the above

Why rubber or plastic used to cover electric wires?

0%
To appear good
0%
They are insulators and do not allow electric current to pass when we touch those wires
0%
To give strength to the circuit
0%
All of the above

When resistors with different resistances are connected in series, which of the following must be the same for each resistor? Choose all correct answers

0%
potential difference
0%
current
0%
power delivered
0%
charge entering each resistor in a given time interval
0%
none of those answers

CBSE Questions for Class 12 Medical Physics Current Electricity Quiz 14 - MCQExams.com

0:0:1

Practice Class 12 Medical Physics Quiz Questions and Answers

CBSE Questions for Class 12 Medical Physics Current Electricity Quiz 14 - MCQExams.com

0:0:1

Practice Class 12 Medical Physics Quiz Questions and Answers

Support mcqexams.com by disabling your adblocker.