Example 3: Using Kirchhoff's rules determine the value of unknown resistance R in the circuit shown in Fig. 2(b). 14(a) so that no current flows through 4Ω resistance. Also find the potential difference between A and D.

Using Kirchhoff's rules determine the value of unknown resistance R in the circuit shown in Fig. 2(b). 14(a) so that no current flows through 4Ω resistance. Also find the potential difference between A and D.

Example 91:In the given circuit as shown in Fig. 2(a). 56, in the steady state, obtain the expressions for (i) potential drop (ii) the charge and (iii) the energy stored in the capacitor C.Example 3:Using Kirchhoff's rules determine the value of unknown resistance R in the circuit shown in Fig. 2(b). 14(a) so that no current flows through 4Ω resistance. Also find the potential difference between A and D.Using Kirchhoff's rules determine the value of unknown resistance R in the circuit shown in Fig. 2(b). 14(a) so that no current flows through 4Ω resistance. Also find the potential difference between A and D.

Using Kirchhoff's rules determine the value of unknown resistance R in the circuit shown in Fig. 2(b). 14(a) so that no current flows through 4Ω resistance. Also find the potential difference between A and D.

v

_{hollow }/ v_{solid}(A) X 1 (B) $\frac{7}{\sqrt{10}}$ (C) $\frac{7}{\sqrt{12}}$ (D) $\frac{\sqrt{21}}{\sqrt{25}}$

Q.4. A trolley of mass 20 kg carries 16 kg grain and moves on a horizontal smooth and straight track at 20 m${s}^{-1}$. If the grain starts leaking out of a hole at the bottom at time t = 0 s at the rate of 0.5 kgs-1, the speed of the trolley at t = 22 s will be nearly

A. 13.5 m${s}^{-1}$

B. 15 m${s}^{-1}$

C. 24 m${s}^{-1}$

D. 26 m${s}^{-1}$

Q.48. A rectangular coil of 300 turns has an average area of 25 cm $\times $ 10 cm. The coil rotates with a speed of 50 cps in a uniform magnetic field of strength 4 $\times {10}^{-2}T$ about an axis perpendicular to the field. The peak value of the induced emf is (in volt)

1) 3 $\mathrm{\pi}$

2) 30 $\mathrm{\pi}$

3) 300 $\mathrm{\pi}$

4) 3000 $\mathrm{\pi}$

Q.14. A bus begins to move with an acceleration of 1 m${s}^{-2}$. A man who is 48 m behind the bus starts running at 10 m${s}^{-1}$ to catch the bus. The man will be able to catch the bus after

(a) 6 s

(b) 5 s

(c) 3 s

(d) 7 s

(e) 8 s