1
WB JEE 2017
MCQ (Single Correct Answer)
+1
-0.25
Change Language
The de-Broglie wavelength of an electron is $$0.4 \times {10^{ - 10}}$$ m when its kinetic energy is 1.0 keV. Its wavelength will be $$1.0 \times {10^{ - 10}}$$ m, when its kinetic energy is
A
0.2 keV
B
0.8 keV
C
0.63 keV
D
0.16 keV
2
WB JEE 2017
MCQ (Single Correct Answer)
+1
-0.25
Change Language
When light of frequency v1 is incident on a metal with work function W (where hv1 > W), then photocurrent falls to zero at a stopping potential of V1. If the frequency of light is increased to v2, the stopping potential changes to V2. Therefore, the charge of an electron is given by
A
$${{W({v_2} + {v_1})} \over {{v_1}{V_2} + {v_2}{V_1}}}$$
B
$${{W({v_2} + {v_1})} \over {{v_1}{V_1} + {v_2}{V_2}}}$$
C
$${{W({v_2} - {v_1})} \over {{v_1}{V_2} - {v_2}{V_1}}}$$
D
$${{W({v_2} - {v_1})} \over {{v_2}{V_2} - {v_1}{V_1}}}$$
3
WB JEE 2017
MCQ (Single Correct Answer)
+1
-0.25
Change Language
Radon-222 has a half-life of 3.8 days. If one starts with 0.064 kg of radon-222 left after 19 days will be
A
0.002 kg
B
0.062 kg
C
0.032 kg
D
0.024 kg
4
WB JEE 2017
MCQ (Single Correct Answer)
+1
-0.25
Change Language
WB JEE 2017 Physics - Electronic Devices Question 9 English
In the given circuit, the binary inputs at A and B are both 1 in one case and both 0 in the next case. The respective outputs at Y in these two cases will be
A
1, 1
B
0, 0
C
0, 1
D
1, 0
EXAM MAP
Medical
NEET
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
CBSE
Class 12