1
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0

If $$P=Q=R=10\Omega$$ and $$S=20\Omega$$, then what resistance should be joined with S to balance the Wheatstone's network?

A
Join a resistance of 10$$\Omega$$ in series with S
B
Join a resistance of 10$$\Omega$$ in parallel with S
C
Join a resistance of 20$$\Omega$$ in parallel with S
D
Join a resistance of 20$$\Omega$$ in series with S
2
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0

To the potentiometer wire of length L and 10$$\Omega$$ resistance, a battery of emf 2.5 V and a resistance R are connected in series. If a potential difference of 1 V is balanced across L/2 length, the value of R in $$\Omega$$ will be

A
1
B
1.5
C
2
D
2.5
3
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0

An electron moves with speed of 2 $$\times$$ 10$$^5$$ m/s along the positive x-direction in a magnetic field $$B = (\widehat i - 4\widehat j - 3\widehat k)\,T$$. The magnitude of the force (in N) experienced by the electron is

A
1.18 $$\times$$ 10$$^{-13}$$
B
1.28 $$\times$$ 10$$^{-13}$$
C
1.6 $$\times$$ 10$$^{-13}$$
D
1.72 $$\times$$ 10$$^{-13}$$
4
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0

A horizontal overhead power line carries a current of 90 A in East to West direction. What is the magnitude and direction of the magnetic field due to the current, 1.5 m below the line?

A
1.2 $$\times$$ 10$$^{-5}$$ T, towards South
B
1.2 $$\times$$ 10$$^{-5}$$ T, towards North
C
1.2 $$\times$$ 10$$^{-5}$$ T, towards East
D
1.2 $$\times$$ 10$$^{-5}$$ T, towards West
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