1
JEE Main 2017 (Offline)
+4
-1
When a current of 5 mA is passed through a galvanometer having a coil of resistance 15$$\Omega$$, it shows full scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range 0 – 10V is:
A
4.005 × 103 $$\Omega$$
B
1.985 × 103 $$\Omega$$
C
2.535 × 103 $$\Omega$$
D
2.045 × 103 $$\Omega$$
2
JEE Main 2016 (Online) 10th April Morning Slot
+4
-1
The resistance of an electrical toaster has a temperature dependence given by R(T) = R0 [1 + $$\alpha$$(T − T0)] in its range of operation. At T0 = 300 K, R = 100 $$\Omega$$ and at T = 500 K, R = 120 $$\Omega$$. The toaster is connected to a voltage source at 200 V and its temperature is raised at a constant rate from 300 to 500 K in 30 s. The total work done in raising the temperature is :
A
400 $$\ln \,{{1.5} \over {1.3}}\,J$$
B
200 $$\ln \,{{2} \over {3}}\,J$$
C
60000 $$\ln \,{{6} \over {5}}\,J$$
D
300 J
3
JEE Main 2016 (Online) 10th April Morning Slot
+4
-1
A galvanometer has a 50 division scale. Battery has no internal resistance. It is found that there is deflection of 40 divisions when R = 2400 $$\Omega$$. Deflection becomes 20 divisions when resistance taken from resistance box is 4900 $$\Omega$$. Then we can conclude :

A
Resistance of galvanometer is 200 $$\Omega$$
B
Full scale deflection current is 2 mA.
C
Current sensitivity of galvanometer is 20 $$\mu$$A/division.
D
Resistance required on R.B. for a deflection of 10 divisions is 9800 $$\Omega$$.
4
JEE Main 2016 (Online) 9th April Morning Slot
+4
-1
A 50 $$\Omega$$ resistance is connected to a battery of 5 V. A galvanometer of resistance 100 $$\Omega$$ is to be used as an ammeter to measure current through the resistance, for this a resistance rs is connected to the galvanometer. Which of the following connections should be employed if the measured current is within 1% of thecurrent without the ammeter in the circuit ?
A
rs = 0.5 $$\Omega$$ in parallel with the galvanometer
B
rs = 0.5 $$\Omega$$ in series with the galvanometer
C
rs = 1 $$\Omega$$ in series with galvanometer
D
rs =1 $$\Omega$$ in parallel with galvanometer
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