1
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A boat is moving due east in a region where

A boat is moving due east in a region where the earth's magnetic field is 5.0 × 10^{-5} NA^{-1}m^{-1} due north and horizontal. The boat carries a vertical aerial 2m long. If the speed of the boat is 1.50 ms^{-1}, the magnitude of the induced emf is

- 0.15 mV
- 0.50 mV
- 0.75 mV
- 1 mV

2
###
A resistor 'R' and 2μF capacitor in series is connected through

A resistor 'R' and 2μF capacitor in series is connected through a switch to 20 V direct supply. Across the capacitor is a neon bulb that lights up at 120 V. Calculate the value of R to make the bulb light up 5s after the switch has been closed. (log_{10}2.5 = 0.4)

- 2.7 x 10
^{6}Ω - 1.3 x 10
^{4}Ω - 1.7 x 10
^{5}Ω - 3.3 x 10
^{7}Ω

3
###
If an ammeter is to be used in place of a voltmeter

If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a

- low resistance in series
- high resistance in series
- low resistance in parallel
- high resistance in parallel

4
###
A wire when connected to 220 V mains supply has power dissipation P1

A wire when connected to 220 V mains supply has power dissipation P_{1}. Now the wire is cut into two equal pieces which are connected in parallel to the same supply. Power dissipation in this case is P_{2}. Then P_{2}:P_{1} is

- 1
- 2
- 3
- 4

5
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An arc lamp requires a direct current of 10 A and 80 V to function

An arc lamp requires a direct current of 10 A and 80 V to function. If it is connected to a 220 V (rms), 50 Hz AC supply, the series inductor needed for it to work is close to:

- 0.08 H
- 0.044 H
- 0.065 H
- 80 H