1
WB JEE 2016
MCQ (Single Correct Answer)
+1
-0.25
Change Language
Two wires of same radius having lengths l1 and l2 and resistivities $${{\rho _1}}$$ and $${{\rho _2}}$$ are connected in series. The equivalent resistivity will be
A
$${{{\rho _1}{l_2} + {\rho _2}{l_1}} \over {{\rho _1} + {\rho _2}}}$$
B
$${{{\rho _1}{l_1} + {\rho _2}{l_2}} \over {{l_1} + {l_2}}}$$
C
$${{{\rho _1}{l_1} - {\rho _2}{l_2}} \over {{l_1} - {l_2}}}$$
D
$${{{\rho _1}{l_2} + {\rho _2}{l_1}} \over {{l_1} + {l_2}}}$$
2
WB JEE 2016
MCQ (Single Correct Answer)
+1
-0.25
Change Language
A hollow metal sphere of radius R is charged with a charge Q. The electric potential and intensity inside the sphere are respectively
A
$${Q \over {4\pi {\varepsilon _0}{R^2}}}$$ and $${Q \over {4\pi {\varepsilon _0}R}}$$
B
$${Q \over {4\pi {\varepsilon _0}R}}$$ and zero
C
zero and zero
D
$${{4\pi {\varepsilon _0}Q} \over R}$$ and $${Q \over {4\pi {\varepsilon _0}{R^2}}}$$
3
WB JEE 2016
MCQ (Single Correct Answer)
+1
-0.25
Change Language
The potential difference V required for accelerating an electron to have the de-Broglie wavelength of 1 $$\mathop A\limits^o $$ is
A
100 V
B
125 V
C
150 V
D
200 V
4
WB JEE 2016
MCQ (Single Correct Answer)
+1
-0.25
Change Language
The work function of Cesium is 2.27 eV. The cut-off voltage which stops the emission of electrons from a cesium cathode irradiated with light of 600 nm wavelength is
A
0.5 V
B
$$-$$ 0.2 V
C
$$-$$ 0.5 V
D
No emission
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