Variation of current passing through a conductor as the voltage applied across its ends as varied is shown in the adjoining diagram. If the resistance (R) is determined at the points A, B, C and D, we will find that
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(a) RC = RD |
(b) RB > RA |
(c) RC > RB |
(d) None of these |
(d) None of these
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Match List I with List II and select the correct answer using the codes given below the lists :
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List I (Position of the object) |
List II (Magnification) |
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(I) An object is placed at focus before a convex mirror |
(A) Magnification is -∞ |
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(II) An object is placed at centre of curvature before a concave mirror |
(B) Magnification is 0.5 |
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(III) An object is placed at focus before a concave mirror |
(C) Magnification is +1 |
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(IV) An object is placed at centre of curvature before a convex mirror |
(D) Magnification is -1 |
|
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(E) Magnification is 0.33 |
Codes :
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(a) I-B, II-D, III-A, IV-E |
(b) I-A, II-D, III-C, IV-B |
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(c) I-C, II-B, III-A, IV-E |
(d) I-B, II-E, III-D, IV-C |
A 500 Hz modulating voltage fed into an FM generator produces a frequency deviation of 2.25 kHz. If amplitude of the voltage is kept constant but frequency is raised to 6 kHz then the new deviation will be
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(a) 4.5 kHz |
(b) 54 kHz |
(c) 27 kHz |
(d) 15 kHz |
A current of 0.1 A circulates around a coil of 100 turns and having a radius equal to 5cm. The magnetic field set up at the centre of the coil is (m0 = 4π × 10–7 weber/amp-metre)
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(a) 2 × 10–5 Tesla |
(b) 4 × 10–5 Tesla |
(c) 8π × 10–5 Tesla |
(d) 4π × 10–5 Tesla |
The energy of hydrogen atom in its ground state is – 13.6 eV. The energy of the level corresponding to the quantum number n is equal 5 is
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(a) – 5.40 eV |
(b) – 2.72 eV |
(c) – 0.85 eV |
(d) – 0.54 eV |