Download CBSE Sample Paper 2024-25 for class 12th to 8th

Sign in

Current Electri...

TIME LEFT -

Question 1
1 / -0

what is $$i$$?

A
$$-4$$mA

B
$$+2$$mA

C
$$+4$$mA

D
$$+8$$mA

Question 2
1 / -0

A potentiometer wire of length $$L$$ and a resistance $$r$$ are connected in series with a battery of e.m.f. $$E_0$$ and a resistance $$r_1$$. An unknown e.m.f. $$E$$ is balanced at a length $$l$$ of the potentiometer wire. The e.m.f. $$E$$ will be given by:

A
$$\displaystyle \frac{LE_0r}{(r+r_1)l}$$

B
$$\displaystyle \frac{LE_0 r}{lr_1}$$

C
$$\displaystyle \frac{E_0 r}{(r+r_1)}. \frac{l}{L}$$

D
$$\displaystyle \frac{E_0l}{L}$$

Question 3
1 / -0

Arrange the order of power dissipated in the given circuits, if the same current enters at point $$A$$ in all the circuits and resistance of each resistor is $$R$$.

A
$$(ii) > (iii) > (iv) > (i)$$

B
$$(iii) > (ii) > (iv) > (i)$$

C
$$(iv) > (iii) > (ii) > (i)$$

D
$$(i) > (ii) > (iii) > (iv)$$

Question 4
1 / -0

A cell of constant $$emf$$ first connected of a resistance $$R_{1}$$ and then connected to a resistance $$R_{2}$$. If power delivered in both cases is same then the internal resistance of the cell is:

A
$$\sqrt {R_{1}R_{2}}$$

B
$$\sqrt {\dfrac {R_{1}}{R_{2}}}$$

C
$$\dfrac {R_{1} - R_{2}}{2}$$

D
$$\dfrac {R_{1} + R_{2}}{2}$$

Question 5
1 / -0

Potentiometer wire of length $$1$$m is connected in series with $$490\Omega$$ resistance and $$2$$V battery. If $$0.2$$mV/cm is the potential gradient, then resistance of the potentiometer wire is?

A
$$4.9\Omega$$

B
$$7.9\Omega$$

C
$$5.9\Omega$$

D
$$6.9\Omega$$

Question 6
1 / -0

Two wire of same metal have same length but their cross-sections are in the ratio 3:1. They are joined in series. The resistance of thick wire is $$10\Omega$$. The total resistance of combination will be

A
$$10\Omega$$

B
$$20\Omega$$

C
$$40\Omega$$

D
$$100\Omega$$

Question 7
1 / -0

Three equal resistors connected in series across a source of emf together dissipate $$10$$ watt. If the same resistors are connected in parallel across the same emf, then the power dissipated will be:

A
$$10\ watt$$

B
$$30\ watt$$

C
$$\dfrac{10}{3}\ watt$$

D
$$90\ watt$$

Question 8
1 / -0

A cell of emf $$E$$ is connected to a resistance $${R}_{1}$$ for time $$t$$ and the amount of heat generated in it is $$H$$. If the resistance $${R}_{1}$$ is replaced by another resistance $${R}_{2}$$ and is connected to the cell for the same time $$t$$, the amount of heat generated in $${R}_{2}$$ is $$4H$$. Then internal resistance of the cell is:

A
$$\cfrac { 2{ R }_{ 1 }+{ R }_{ 2 } }{ 2 } $$

B
$$\sqrt { { R }_{ 1 }{ R }_{ 2 } } \times \cfrac { 2\sqrt { { R }_{ 2 } } -\sqrt { { R }_{ 1 } } }{ \sqrt { { R }_{ 2 } } -2\sqrt { { R }_{ 1 } } } $$

C
$$\sqrt { { R }_{ 1 }{ R }_{ 2 } } \times \cfrac { \sqrt { { R }_{ 2 } } -2\sqrt { { R }_{ 1 } } }{ 2\sqrt { { R }_{ 2 } } -\sqrt { { R }_{ 1 } } } $$

D
$$\sqrt { { R }_{ 1 }{ R }_{ 2 } } \times \cfrac { \sqrt { { R }_{ 2 } } -\sqrt { { R }_{ 1 } } }{ \sqrt { { R }_{ 2 } } +\sqrt { { R }_{ 1 } } } $$

Question 9
1 / -0

A potentiometer (variable resistor) is connected in a simple circuit as shown below.
The student varies the resistance on the potentiometer and measures the corresponding current in the circuit. The table of data and the resistance vs. current graph created by the student is shown below.
$$R$$ (Ohm)

$$I$$ (A)
0.5 5.99
1.0 3.02
1.5 2.07
2.0 1.56
2.5 1.19
3.0 1.04
3.5 0.83
4.0 0.72
4.5 0.70
5.0 0.62
5.5 0.53
6.0 0.49
6.5 0.45
8.5 0.36
9.0 0.33
9.5 0.31
10.00 0.29
Based on the experimental data collected by the student, determine the emf of the battery.

A
0.33 V

B
0.5 V

C
1.0 V

D
2.0 V

E
3.0 V

Question 10
1 / -0

The temperature coefficient of resistance of a wire is $$\displaystyle { 0.00125 }/{ ^{ \circ }{ C } }$$. Its resistance is $$\displaystyle 1\Omega $$ at $$300\ K$$. Its resistance will be $$\displaystyle 2\ \Omega$$ at:

A
$$1127\ K$$

B
$$1400\ K$$

C
$$1154\ K$$

D
$$1100\ K$$

Submit Test

User

Question Analysis

Answered - 0
Unanswered - 10

1
2
3
4
5
6
7
8
9
10

Submit Test

Self Studies

Get latest Exam Updates
& Study Material Alerts!

No, Thanks

Click on Allow to receive notifications

Allow Notification

Self Studies

Self Studies

To enable notifications follow this 2 steps:

First Click on Secure Icon
Second click on the toggle icon

Allow Notification

Get latest Exam Updates & FREE Study Material Alerts!

Self Studies

×

Open Now

"Enter your details to claim your prize if you win!"

Send OTP

Processing, please wait...

I agree to the Terms of Use & Privacy Policy